Transitioning BM to a clean codebase will take several more years. Why not start fresh?
The answer to that is the same as it was eight years ago when I joined the dev team, and however many years ago it was when you effectively left it to work on Might and Fealty.
Sure, I'd love to see BattleMaster rewritten with a clean codebase in something like Symfony. But given the available developer time, that would require abandoning the idea of fixing any current bugs that aren't completely game-breaking for RL
years before we had something that could hope to replace the existing game code.
The quickest way to start making a difference, building a parallel system that we could use to replace individual scripts one by one, we would still have to write the entire highly-interconnected model infrastructure before we could start working on a single user-facing script, and in this scenario we'd be stuck with the existing database structure (which I would dearly love to replace, as well).