Sorry to ask such basic questions but there was a recent post indicating that an attempt to update the genius to 22.5.0 caused major issues.
Is this version known to work for others, or should I just use the 22.4.0?
Also which firmware upload method should I use for the sysex upload?
I think the easiest way for you to figure out what works best is just to try those releases yourself. However 22.5.0 has an important bugfix for Genius - apparenly its UI code crashed if you end up sending a negative value as CV out signal. So using it would be ideal if it works.
If you’re not sure what to do, you can use either OpenWareLaboratory or Rebeltech patch library.
It may be a good idea to erase your patches after firmware update, especially if you have some issues. But it’s not strictly necessary, only if there’s some changes to flash storage format and that didn’t happen on every release.
Thanks very much for your advice. 
Once I’m back from my trip, I’ll try to flash the 22.5.0 firmware using OpenWareLaboratory. I’ll report back if I’m successful or otherwise.
S