HDHomeRun Flex use ATSC 1.0 channels over 3.0 channels

I'm moving on from my Tablo setup and looking at getting the HD Homerun Flex. Trying to decide between the Flex 4k or Flex Quad. When scanning channels can I choose the 1.0 stations and ignore the 3.0 stations (for now anyway) or does the scanning always default to 3.0 stations with 1.0 as a fallback?

I see there are apps for iOS, Windows and Roku so that is good. Assuming you can see EPG and setup recordings on all platforms. Correct?

I run an Emby server, is there DVR integration with HD Homerun? I know there is for Plex but not sure about Emby.

Any other recommendations for the 4K or Flex Quad? I live in the San Antonio, TX area if that matters. TIA.