DMA issues with the A3000 as well
The Amiga 3000 included an onboard Western Digital 33C93 SCSI controller chip as opposed to the Amiga 4000's onboard IDE controller. Problem was that the 33C93 included a DMA bug that could lock up the machine under the right circumstances. I rarely triggered it while running AmigaOS, but I hit it all the time running NetBSD.
I worked around the problem by installing a Zorro II SCSI card, but it was terribly slow since ZII DMA was disabled on the ZIII bus. Eventually WD released a bugfixed 33C93A chip that resolved the corruption problem, but I had moved on to using an A4000 by that point.
I was lucky in that my Amiga 4000 included an r11 Buster, so eventually I fitted it with a DKB 4091. I also tried adding an A3640 processor card, but apparently it was too much for the system and it completely fried after a couple of hours.
So I pulled out my old A3000 and then transferred the r11 Buster, 4091, and Cybervision 64 to it. It lived on a few more years mostly running Shapeshifter (Mac emulator) running System 7.