Hey @Tumbleweed , I just used your instructions on a 2GB CF card in an A600 and they worked first time.
Here's the details for anyone else trying to replicate and might have issues.
DH0: OS3.1, non-bootable, FFS, 100MB
DH1: OS3.2.3, bootable, FFS, 100MB
DH2 and DH3: non-bootable, PFS\03, 800MB each. I used Quick Format and the HDInstTools that came with 3.2.3.
Mostly Stock A600: Has a 3.2 ROM and 8MB of Fast.
If your using 3.2, you should not have the any issues, regardless of sizes.
Latest FFS does not have drive size limitations, same goes for PFSAIO.
As a test, I booted off a 20GB boot partition, without issues. That was using both FFS and PFSAIO as seperate tests.
Your A600 is begging for a Pistorm 600,

.