I'm pretty sure the flash module would still have to interact with the base system, so I'd say it wouldn't work. Handspring has the different physical hardware, which would make a big enough difference that the two OS's don't have parity.
With Handspring's announcement of going all wireless, there is some uncertainty in the community as to how to proceed. To me, their lack of response to PalmOS 4 is even more unsettling.