I recently picked up a barely-used Platinum IIe and wanted to fill my MicroDrive HD up with games. I ran across this HD image which is loaded with DOS games, including my favorites from Broderbund, that you can run from ProDOS using the program DOS 3.3 Launcher:
If you remove the GS startup system file (I forget which one it is) then in boots directly into FastBoot which lives up to its name. 32 megs of DOS gaming goodness!
Attached is the HD image that boots directly to FastBoot.