Interesting that there are binaries of synth gear "out there." I never looked for them, though I seem to recall stumbling onto a table that firmware updates (maybe for some Roland gear) with the caveat that they cannot be posted due to copyright issues, but if people look they can find them.
As a VZ-8m owner, I would be interested if anyone (1) has the binary, (2) can hack it, (3) can reverse engineer it, and (4) can figure out how to tweak it and create new firmware.
Other than the battery (which lasted a decade or two longer than it was supposed to), it seems to me that the hardware/circuits have withstood the test of time!!!! Actually, I think one of my original batteries just died withing the past 5 years--so that certainly lasted longer than expected.
And I agree--the explanation for why there has been no firmware updates makes sense.
Steve