My guess is that a 3-0-1 map probably transforms into a proper 4-0 map if Republicans "go back to normal" electorally. Though haven't plenty of dems won the UT-04 district, even pre-Trump?
Yes, but I'd guess the point is that they wouldn't make it any easier for a Dem to win again.
Here is my attempt at a 3-0-1 map like I said. I also tried to have road contiguity in all districts; if you allow districts with no road connection it gets quite a bit easier. I however did not consider incumbent residences so this probably would not work.