I wonder if any of these issues are potentially related to what IComp and Dave Haynie are attempting to resolve in Buster v12 (below)?
"During the interview of the Amiwest event, we've announced the "Buster-12" project, which will begin before Christmas of this year. In cooperation with Commodore chip designer Dave Haynie, we're developing a bug-fixed version of the Buster chip that will allow more than one DMA bus master card and that will fix other known bugs of the previous "best" Version 11 of the chip. The product, which plugs into the socket of the Super Buster of an A3000 or A4000 computer, will presumably be available in the second half of 2021."
https://icomp.de/shop-icomp/en/33/it...d-of-2020.html