I'm not sure how exactly the new firmware features will be handled, but in general an AZW3 is an AZW3 regardless of whether Amazon made it or calibre made it. We *may* need to decode some secret sauce, potentially, for the new features.
As for collections, there is a calibre plugin that works in tandem with an on-device hack, but that won't work unless you do hardware modding to get the Kindle jailbroken in the first place.
Lots of people will tell you that calibre plugboards to prepend the series to the title make a
perfectly fine adequate substitution.
P.S. Welcome to the dark side.
