Major upgrades / suse base


I am planning to move from FreeNAS to RockStor and a few questions came up for me:

The documentation says, that doing a major upgrade basically means a re-install. Sure you say you try to keep those to a low frequency but eventually one will come along.
My question is: What exactly do you mean with complete reinstall? Can I just re-mount my existing data pools? Will I need to configure all my services again? Can I maybe export the settings? Are there helper tools to make it a smoother experience?

Additionally, you’re currently working on moving to suse. Will that change be a major upgrade? Would I need to reinstall soon if I were to install rockstor now? Should I start immediately with the beta program of the suse base? (I have linux experience, but more debian/ubuntu/archlinux, no suse)

For anyone curious, I found pretty much all my questions answered by this reply: Rebasing on to openSUSE?