Yes, but that's probably fixable with some lines in config.ini, for example, to increase the amount of memory the player thinks it has - sort of a negative cache reserve line, as you might want space kept aside for other tasks running on the player.

I can confirm that a correctly modded kernel lets my MkII be 16MB with no problems.

Stacking multiple chips will run into the drive cradle, which is a bit of an issue. One thing that currently worries me is the select line, which goes to the StrongARM and the two stacked chips, and it looks pretty fragile and susceptible to being whacked by the drive cradle. Needs some sort of protection from this (above the couple of bits of insulation tape I'm using!)

Hugo