Something I've been playing around with that I don't see many ROB player use: Boost-land (Boost>Waveland). Basically do waveland at the later frames of boost, when you can act out of it. This technique also seems very useful I think, and can improve his mobility and increase his options.
Applications:
1) More options out of boost: With this technique you have another option out of boost, so you don't have to commit to an attack or boost back again. If the opponent is shielding you can wave-land boost, or empty-boost, and grab, jab or wave land backwards and bait out an OOS option.
2) Movement: With this technique you have more movement options. Like short hop (immediate) boost-waveland, doing a very low boost and then wavelanding out of it, you could call this Boost-Dashing if you want. You can also do a higher boost, but then you need to airdodge down and then waveland and is therefore more sloppy and react-able.
3) Platform Movement: I don't know how good this is but you can do some fancy platform movement with it as well. If you do a boost horizontally above the platform, you can do a waveland (or perfect waveland). You can also wavedash of a platform, or the stage, and (immediately) do a boost back to the platform.
4) Reach the Top Platform: Similar to 3), you can boost vertically up to the top platform. It could be used as a read if they're up there with boost-waveland > U-smash/Grab/U-tilt. U-smash could potentially kill floatier characters early and grab U-throw can do that as well.
5) Recovery: This technique can also be used to give more recovery options. First of you can boost horizontally and waveland on a platform or the stage. You can also boost vertically and waveland onto a platform or the stage. This can be good if your opponent is, for some reason shielding, and trying to shield a boost u-air stall, then you can boost up and waveland horizontally and back onto the stage. You can also do this onto a platform, like the smashville platform for example.
6) Ledge Shenanigans: You can do some stuff with this on the ledge as well. First of you can boost back to the stage, with a waveland alternatively, like Fox and Falco. If you're quick you'll even have some intangibility frames to cover up for you, like Fox and Falco has as well. You can also do a pseudo Hax-dash with by releasing ledge>jump>Boost-land off the ledge>grab the ledge again. This isn't that usefull I think, since I'm pretty sure you can't stay fully invincible doing this. It could be a cool mixup however. I don't know if this is a faster re-grab than to drop ledge>jump>boost into the wall>re-grab, it might be faster actually especially if you fas-fall when you're wavelanding off the stage and grabbing the ledge. One more advantage of this is that you refresh your boosts, so you now have all 3 boosts back rather than if you do the boost-into-wall-stall, where you lose a boost doing so.
7) Picking up Items: Because you waveland, you can also pick up items with this technique.
Advantages:
-More mobility/movement options
-More options out of boosts
-Looks somewhat flashy
Disadvantages/Limitations:
-YOU CAN ONLY DO THIS ON THE FIRST 2 BOOST, NOT ON THE LAST. Not that big of a deal actually, but still an important limitation.
-You can act out of boost very late in general, if you're not doing an airial. So it's worse than Ike's Quick Draw>Wave-Dash, or Sonic's Side-B>Wave Dash.