So after all this time, and generally maintaining the feels that Roy is great just a tad undertuned, I'm pretty sure with 3 number changes we'd have a character approaching high tier.
By design, his recovery is meant to be a huge shortfall - while adding super armor to aerial up-b would come close to nullifying the issue, I believe with just a bit more strength behind his basic game plan things will align well with what was an intentional design decision (rockets and explodes like Fox, swords like Marth [with a little bit of Ike]).
- Neutral Air Second Strike: Strong Hit Damage: 8.5 -> 9
- Forward Air: Strong Hit Damage: 11.0 -> 12.x
- Back Air: Strong Hit Damage: 12.0 -> 12.5
What Roy is really lacking right now is some adhesion. He is too reliant on rage to function - if he's just lost a stock and has no rage he only has high risk moves to KO with, and even then many won't KO as his moves have high base and so-so growth. There's a sweetspot where knockback on his stringing moves (tipper attacks, jab) are primed, but he cannot reliably link into things (aerials) which will clinch stocks. If you DI Jab in at the ledge and get faired/baired at over 100%, I think it's reasonable that he should be getting stocks (as does Marth, and most other FE characters, let alone the rest of the cast). This rectifies many issues, both his ability to reset stocks and his pressure.
Back Air matches Marth's damage, Neutral Air is 0.5% damage less and Forward Air as his most unique contrast to Marth (with it's higher start up/etc) comes out at least 0.5% more. The major difference between 12.5 and 12.0 is shield stun; -5 and -4 on block is quite large in terms of options (hello being able to spot dodge grabs).
I've had someone hack/alter their game with these values and they've been extremely surprised and impressed with the differences in abilities, if you are so inclined I'd recommend doing something similar
Roy's back air is his best aerial, the sour hit scales very strong so it comes out as a KO move often while sweetspot nair/fair aren't able, otherwise being able to combo/set up longer due to it's very low base. The sweet spot is the only aerial he can otherwise KO with in off stage situations without rage (or just in general), I don't think this was ultimately intended seeing as how much effort and nuance was attempted with his Forward Air.
Marth would still maintain a notably stronger neutral air, have a slightly worse scaling back air but a higher base (roughly even; still stronger KO power at 100%), and forward air will be a stronger move from roughly 100% onward but weaker before hand (referring to 12.0 here, 12.5 difference does matter a bit, making it weaker until 120%~).
Considering the mobility differences, ratio of sweet spot to not ("difficulty"), the existence of our throws and jab, and the higher base (rage!), forward air being weaker as a KO move seems reasonable. 12.0% still gives us a -4 fair if it's fresh, 12.5% would still make sense though.
The other things which would be nice:
Up Tilt end lag reduced
Aerial Blazer with super armor and/or higher damage on the final hit (still weaker than the grounded, but not 'doesn't ko at 200%' type of suffering)
A lot more weak hits following back air's numbers, or alternatively growth rates which are slightly lowered.
Why am I saying this?
I don't think it's certain there will be future patches, but I do think there is a lot of misunderstanding about Roy in the general public. They (Lancer types of people) can't seem to get that a character that has a moveset like Marth but doesn't seem to be as easy to use isn't terrible. While we can't rely on and dream there will be another patch to make Roy better, I think if we all understand how small the amount of changes would actually be necessary to push Roy towards very viable, we'll be in a better spot to formulating a game plan that works with what we do have. It may be our shortfall that we need to keep back air fresh for KOs and we otherwise have to be hard-reading Ike Mofos if we're ever at a deficit; and us figuring out cool traps and other set ups into our smash attacks in such situations will be the alternative style of play we have to flip flop between for success. Life would be a lot easier with stronger aerials, but the path needn't be easy.