I rip 4k, and 1080, then convert 1080 to 720.
there is no reason to keep a huge 1080 rip if you have a 4k that can direct play.
anyone not direct playing a 4k, can eat 720.
there are a number of ways you can do it (4k), only you can decide what is best for you.
this may or may not be helpful, read the whole thread @ Plex, 4k, transcoding, and you
