Ok, so Today I decided to pick one of my Sudachi and one of my citrangequats to compare since I will be moving in a few years.
Make sure you put a clear label on the plant so the new home owner will know what it is.
If the new owner knows what it is, they are more likely to take care of it or not rip it out. Labels can be made from write-on metal tags.
I find Thomasville to be surprisingly edible for a trifoliate hybrid, very little of the poncirus taste. I can eat them. A little bit of a kumquat mandarin orange and lime-like in a way flavor, not the best quality flavor but satisfactory, you could eat them or find some culinary uses.
Sudachi is higher quality. More lime and Yuzu-like. Its peel is also somewhat edible. Maybe the peel is slightly tougher than citrangequat but also a little better flavor.
Citrangequat is a more vigorous grower than Sudachi, which doesn't seem to have much vigor at all, but in terms of how much cold they can tolerate, I think they seem to be similar. My Sudachi here in zone 8a PNW area seems to be doing just okay and surviving. Even managed to produce a few little fruit druplets, maybe the plant's fruits will be able to ripen in later years when the plant grows bigger.
Maybe citrangequat can tolerate more cold but it will not do well, will suffer some die-back in temperatures colder than what the Sudachi can take.