I noticed this thread about a project with the same name: https://forum.silphco.io/threads/leons-ultimate-firered-rom-base-unofficial-expansion-project.285/
Is that about your project? It seems originally someone called petuuuhhh was in charge of this project, then they quit and handed over power to DeathOrDoom0 to be in charge, then PSI Master (Leon) asked DeathOrDoom0 to discontinue the project, then DeathOrDoom0 agreed and said “Alright. The project has been canceled.”
Which seems strange, because now you are announcing the same project that supposedly got discontinued. Also PokéCommunity is a much more active site, there is a thread about Leon's Ultimate FireRed ROM Base there, I see a lot more feedback about it there, with version 3.0 of it recently coming out: https://www.pokecommunity.com/showthread.php?t=409672
Then again looking at the dates, I guess it makes sense. Leon wanted the project canceled since the base ROM was going to be changed a lot. But now Leon seems to be putting the base ROM thing on hold to work on another project, Pokémon Wish, instead. Which means the reason Leon asked this project to be discontinued, namely, Leon said “I never actually gave any permission to Petuuuhhh to expand on my rom base, and I had dismissed it at every opportunity it was brought up. Another issue would arise due to the fact that my base is continuously being worked on, so releasing a new base using an inferior version would lead to compatibility issues as well.” That whole reason is apparently irrelevant now.
Since more recently Leon has said upon releasing version 3.0, “This MAY or MAY NOT be the final version. Its known limitations are there plain as day, and I will try to fix them when I get the know-how to do so. In the meantime, I feel the base speaks for itself more than I ever could, so please enjoy and get out there! Make some quality hacks we all can enjoy!” Which seems to indicate now it is not being updated as much and now Leon has a more permissive attitude towards hacks based on it than a month ago. So I guess Leon, who told you to stop, is now giving you permission to start again?
Anyway, good luck with all this. Too complicated for me to follow all that. In fact, I don’t even know what I just typed, or copied and pasted, or whatever. Still though, as someone who is enjoying Unofficial Pokémon Throwback right now, a FireRed hack by RichterSnipes and tkim available at http://www.romhacking.net/hacks/4147/
, if you manage to make something even better than that, I will be impressed.
I guess you are working on an even expanded base for other hacks, though, rather than a hack intended to be played on its own. So for instance, people would be able to have an 807 hack on top of your hack to include all 807 Pokémon from Generations 1 thru 7 and Alolan forms and Mega Evolutions and all of that other stuff. Or would you include all of that in your hack and just make it optional how many generations of Pokémon individual hacks add into the actual game, i.e. add game data for all existing Pokémon but not make them catchable in any locations on the map? So that save games from different hacks based on your base hack would be able to trade Pokémon with each other since the same data would be there for all of them?
Anyway it sounds like a good idea, good luck, I hope there is not any more drama with you being asked to stop this hack again. Because it sounds very promising.