Tip: Switch palace switches normally disappear if you replay the level. However, if you insert them as direct Map16 and use the hex edit at $00EEB2 in the ROM map, you can replay the level without a problem.
Subroutine run on bounce sprite INIT (for all bounce sprites except turnblocks), which is responsible for the bug where a coin on top of hittable block and hitting said block will cause the coin to turn into an invisible solid block.
Change $0290ED from  to [AD] to prevent the coin from being collected.
Change to [20 1E D5], and change $02D51E from FF FF FF FF FF to A9 02 4C BA 91, to fix the glitch where placing a coin above a ? block or turn block will cause the coin to leave behind an invisible solid block if the block below is hit.