Did you make sure that your XML has support for Expansion stages? If I remember correctly, Bionic's modlauncher does not have support for Expansion Stages, so you'll have to add support for them yourself.
I believe so. As far as I know, the version I am using is compatible with all modes besides BBrawl. I'm not using that one.
[COLLAPSE="Spoiler"]<patch id="tex_stage">
<folder external="/brawlmods/stages" disc="/stage/melee/" recursive="true" resize="true" />
<file external="/brawlmods/stages/st_battle.rel" disc="/module/st_battle.rel" />
<file external="/brawlmods/stages/st_battles.rel" disc="/module/st_battles.rel" />
<file external="/brawlmods/stages/st_config.rel" disc="/module/st_config.rel" />
<file external="/brawlmods/stages/st_crayon.rel" disc="/module/st_crayon.rel" />
<file external="/brawlmods/stages/st_croll.rel" disc="/module/st_croll.rel" />
<file external="/brawlmods/stages/st_dolpic.rel" disc="/module/st_dolpic.rel" />
<file external="/brawlmods/stages/st_donkey.rel" disc="/module/st_donkey.rel" />
<file external="/brawlmods/stages/st_dxbigblue.rel" disc="/module/st_dxbigblue.rel" />
<file external="/brawlmods/stages/st_dxcorneria.rel" disc="/module/st_dxcorneria.rel" />
<file external="/brawlmods/stages/st_dxgarden.rel" disc="/module/st_dxgarden.rel" />
<file external="/brawlmods/stages/st_dxgreens.rel" disc="/module/st_dxgreens.rel" />
<file external="/brawlmods/stages/st_dxonett.rel" disc="/module/st_dxonett.rel" />
<file external="/brawlmods/stages/st_dxpstadium.rel" disc="/module/st_dxpstadium.rel" />
<file external="/brawlmods/stages/st_dxrcruise.rel" disc="/module/st_dxrcruise.rel" />
<file external="/brawlmods/stages/st_dxshrine.rel" disc="/module/st_dxshrine.rel" />
<file external="/brawlmods/stages/st_dxyorster.rel" disc="/module/st_dxyorster.rel" />
<file external="/brawlmods/stages/st_dxzebes.rel" disc="/module/st_dxzebes.rel" />
<file external="/brawlmods/stages/st_earth.rel" disc="/module/st_earth.rel" />
<file external="/brawlmods/stages/st_emblem.rel" disc="/module/st_emblem.rel" />
<file external="/brawlmods/stages/st_famicom.rel" disc="/module/st_famicom.rel" />
<file external="/brawlmods/stages/st_final.rel" disc="/module/st_final.rel" />
<file external="/brawlmods/stages/st_fzero.rel" disc="/module/st_fzero.rel" />
<file external="/brawlmods/stages/st_greenhill.rel" disc="/module/st_greenhill.rel" />
<file external="/brawlmods/stages/st_gw.rel" disc="/module/st_gw.rel" />
<file external="/brawlmods/stages/st_halberd.rel" disc="/module/st_halberd.rel" />
<file external="/brawlmods/stages/st_heal.rel" disc="/module/st_heal.rel" />
<file external="/brawlmods/stages/st_homerun.rel" disc="/module/st_homerun.rel" />
<file external="/brawlmods/stages/st_ice.rel" disc="/module/st_ice.rel" />
<file external="/brawlmods/stages/st_jungle.rel" disc="/module/st_jungle.rel" />
<file external="/brawlmods/stages/st_kart.rel" disc="/module/st_kart.rel" />
<file external="/brawlmods/stages/st_madein.rel" disc="/module/st_madein.rel" />
<file external="/brawlmods/stages/st_mansion.rel" disc="/module/st_mansion.rel" />
<file external="/brawlmods/stages/st_mariopast.rel" disc="/module/st_mariopast.rel" />
<file external="/brawlmods/stages/st_metalgear.rel" disc="/module/st_metalgear.rel" />
<file external="/brawlmods/stages/st_newpork.rel" disc="/module/st_newpork.rel" />
<file external="/brawlmods/stages/st_norfair.rel" disc="/module/st_norfair.rel" />
<file external="/brawlmods/stages/st_oldin.rel" disc="/module/st_oldin.rel" />
<file external="/brawlmods/stages/st_orpheon.rel" disc="/module/st_orpheon.rel" />
<file external="/brawlmods/stages/st_otrain.rel" disc="/module/st_otrain.rel" />
<file external="/brawlmods/stages/st_plautena.rel" disc="/module/st_plautena.rel" />
<file external="/brawlmods/stages/st_pictchat.rel" disc="/module/st_pictchat.rel" />
<file external="/brawlmods/stages/st_pirates.rel" disc="/module/st_pirates.rel" />
<file external="/brawlmods/stages/st_plankton.rel" disc="/module/st_plankton.rel" />
<file external="/brawlmods/stages/st_stadium.rel" disc="/module/st_stadium.rel" />
<file external="/brawlmods/stages/st_stageedit.rel" disc="/module/st_stageedit.rel" />
<file external="/brawlmods/stages/st_starfox.rel" disc="/module/st_starfox.rel" />
<file external="/brawlmods/stages/st_tbreak.rel" disc="/module/st_tbreak.rel" />
<file external="/brawlmods/stages/st_tengan.rel" disc="/module/st_tengan.rel" />
<file external="/brawlmods/stages/st_village.rel" disc="/module/st_village.rel" />
<file external="/brawlmods/stages/st_custom1.rel" disc="/module/st_custom1.rel" create="true" />
<file external="/brawlmods/stages/st_custom2.rel" disc="/module/st_custom2.rel" create="true" />
<file external="/brawlmods/stages/st_custom3.rel" disc="/module/st_custom3.rel" create="true" />
<file external="/brawlmods/stages/st_custom4.rel" disc="/module/st_custom4.rel" create="true" />
<file external="/brawlmods/stages/st_custom5.rel" disc="/module/st_custom5.rel" create="true" />
<file external="/brawlmods/stages/st_custom6.rel" disc="/module/st_custom6.rel" create="true" />
<file external="/brawlmods/stages/st_custom7.rel" disc="/module/st_custom7.rel" create="true" />
<file external="/brawlmods/stages/st_custom8.rel" disc="/module/st_custom8.rel" create="true" />
<file external="/brawlmods/stages/st_custom9.rel" disc="/module/st_custom9.rel" create="true" />
<file external="/brawlmods/stages/STGCUSTOM1.pac" disc="/stage/melee/STGCUSTOM1.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM2.pac" disc="/stage/melee/STGCUSTOM2.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM3.pac" disc="/stage/melee/STGCUSTOM3.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM4.pac" disc="/stage/melee/STGCUSTOM4.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM5.pac" disc="/stage/melee/STGCUSTOM5.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM6.pac" disc="/stage/melee/STGCUSTOM6.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM7.pac" disc="/stage/melee/STGCUSTOM7.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM8.pac" disc="/stage/melee/STGCUSTOM8.pac" create="true" />
<file external="/brawlmods/stages/STGCUSTOM9.pac" disc="/stage/melee/STGCUSTOM9.pac" create="true" />
<file external="/brawlmods/stages/STGDXONETT.pac" disc="/stage/melee/STGDXONETT_en.pac" />
<file external="/brawlmods/stages/STGDXPSTADIUM.pac" disc="/stage/melee/STGDXPSTADIUM_en.pac" />
<file external="/brawlmods/stages/STGGW.pac" disc="/stage/melee/STGGW_en.pac" />
<file external="/brawlmods/stages/STGHOMERUN.pac" disc="/stage/melee/STGHOMERUN_en.pac" />
<file external="/brawlmods/stages/STGMADEIN.pac" disc="/stage/melee/STGMADEIN_en.pac" />
<file external="/brawlmods/stages/STGNEWPORK.pac" disc="/stage/melee/STGNEWPORK_en.pac" />
<file external="/brawlmods/stages/STGPICTCHAT.pac" disc="/stage/melee/STGPICTCHAT_en.pac" />
<file external="/brawlmods/stages/STGRESULT.pac" disc="/stage/melee/STGRESULT_en.pac" />
<file external="/brawlmods/stages/STGSTADIUM.pac" disc="/stage/melee/STGSTADIUM_en.pac" />
<file external="/brawlmods/stages/STGVILLAGE_00.pac" disc="/stage/melee/STGVILLAGE_00_en.pac" />
<file external="/brawlmods/stages/STGVILLAGE_01.pac" disc="/stage/melee/STGVILLAGE_01_en.pac" />
<file external="/brawlmods/stages/STGVILLAGE_02.pac" disc="/stage/melee/STGVILLAGE_02_en.pac" />
<file external="/brawlmods/stages/STGVILLAGE_03.pac" disc="/stage/melee/STGVILLAGE_03_en.pac" />
<file external="/brawlmods/stages/STGVILLAGE_04.pac" disc="/stage/melee/STGVILLAGE_04_en.pac" />
</patch>[/COLLAPSE]
If I had to guess, I'm assuming this is the patch of code I need to work with. Right now I'm just trying to load STGCUSTOM01.pac and haven't even attempted to get the other ones beyond 09 to work. I no longer believe this is a mere directory issue, as I literally have this file placed in about 10 different locations within various folders called stage and stages, inside of each other and in the root directory of brawlmods. So at least one should one recognized, or so I'm under the impression.
Seeing as how I'm getting no where, it is pretty obvious I am not understanding these guides embedded within the .XML, which is embarassing to admit, but those appear to be the only guides available.
[EDIT] Through some mess, I managed to get a stage expansion of 9 to work. I've know idea how I pulled it off, but I think I can figure what I need to out from this. Thank you for providing me the hint I need.