[afedchin]

Does it use "C:\Users\[user]\AppData\Roaming\Kodi" to store its config data like the exe version does? Can I install the store version on top of the already installed exe version, or do I need to uninstall the exe version first?

It uses this folder once on first start and makes shadow copy of it to another location. We can't control this, this "feature" of desktop bridge. You can install both, but can't launch both at the same time.
 

For some reason I am able to mount my SMB share but I dont have the SMB addon enabled as it isn't showing in my addon repository.

the addon is available for UWP version only.