I took the screenshot with the "+" before I realized it'd be easier for now to ignore the "+". This is my fault for being lazy, I'll change it. I looked at a database of lichess games (40,000) to convince myself that non-Queen promotions were worth ignoring for the beta. If promoting to a different piece is clearly the better move, I could run a Stockfish check anytime a promotion move is made to assume the player chose the best non-Queen promotion (since otherwise you'd just promote to a Queen in a serious game)
I suppose it's unlikely to happen in a game serious/slow enough that people are bothering to record it on paper and upload it, but I've tricked someone into stalemating me by promoting to a queen before. Long term I don't think assuming people made the best move is the right decision.
Thanks! Definitely, the check and mate things should also be fixed long term. The nice thing is, I was able to put in tons of constraints to improve processing (for example the last two boxes must be a square like e4) if I ignore checks.
You could also 'assume queen until proven otherwise.' eg, if all remaining moves are diagonal, it stays a queen (even if it was really a bishop). And switch to an =K if you see a knight move (or the checkmate requires it to be a knight).
