None of those have anything to do with the platform firmware. The hub is layered... Linux, then the Platform, which is Java mostly. Then comes your layer.. register, create a name, location, Rules and automations and the devices attached. Around here we lump all of that, your layer into "The DB".
Soft Reset simply blows away almost all of The DB, without losing your registration and so on. Rules and Automations are removed. Hard Reset goes a head and blow it all away.. pretty much how you'd want it to be if you were selling it. No trace of 'you' left. Therefore, stay as far away from a Hard Reset as you can, without some highly trusted advice to use it.
The Diagnostic Menu for Download Latest and Restore Previous are the way you affect the Platform... v2.0.8 to 2.2.5
If it were me, I'd try and follow the upgrade steps found in most of the 2.2.5 topics:
