Turns out, I am stupid :D I didn't realise that there were settings for the cylindrical map. Turns out they help quite a bit :D UV map done, not just got to pack it: I can't see any major distortion either:
It looks like maybe you didn't specify a target/highpoly mesh during the bake. Are there ray misses? Your previous bake (with the holes on the ends) didn't have the same issue. Whenever you need help with baking stuff it helps to post the bake, pics of the HP and LP and cage, settings etc. There are lots of things that can…
Dox, it's your project, I say do whatever keeps you learning. If getting the perfect bake is so frustrating that you feel like you don't want to work on your project anymore, get on to texturing and just finish the damn thing! And as long as you keep the same UVs you can try to bake again later down the line after it's…