You can just use an ADF-reading program in WinUAE to create an ADF from the IPF.
I think I missed patching another bit of code which limits the think time to a minimum of 3 seconds. Second try uploaded to The Zone and
Code:
https://www.media!fire.com/file/19kzbcz7l072lj1/BattleChess_fast_try2.lha