I used HDL 48bit and took all the partition sizes down to 0MB, except for the one you can enter a name for, which I called "+OPL" and made 2048MB (2GB). This should be enough storage for plenty of VMCs and plenty of cover/disc art if you want to make use of them. I also use it as general homebrew storage, made a folder within +OPL and put a bunch of stuff in there.
Chip-free/MC-free homebrew <3
FMCB 1.93 on MC for emergencies, NA
250GB HDD/FHDB 1.93/OPL 0.9.2 (GSM and non-GSM)/PS2 games, NO HDDOSD
80GB HDD/FHDB 1.93/POPStarter rev12/OPL644/GSM0.37/PS1 games, NO HDDOSD
SCPH-75001 (sitting idle, slims suck):
FMCB 1.92 on MC