And this type of problem would go away if ANY style of memory was added? I uess I'm asking if the HD buffers ONLY use CHIPMEM... So, er, does it?
The buffer allocation code just asks for whatever memory is available. Therefore, higher priority memory types will always be used in preference. If any FastRAM is fitted, it will be used instead of Chip RAM which is considered low priority. Normally, where Fast memory is available you only allocate Chip RAM to satisfy a particular need, such as a sprite, bitplane, copperlist or sound buffer or whatever.