100% this. Sutures are not to be done in the field.
Dealt with a nasty flap avulsion once. Knew it was going to need stitches but we knew we couldn't/shouldn't do them in the field. Put a non-stick pad under the flap, wrapped with a metric ton of gauze and a compression bandage. ER Doc thanked us profusely saying it would have been 10x more painful to rip out hastily done stitches and separate the skin (
not to mention infection risk) and also applauded our decision to insert the non-stick pad. It made (
re)cleaning the wound easier and allowed them to remove some potentially necrotic tissue before they stitched it up. By leaving the flap on there it also prevented them from needing to do a skin graph. They ended up applying three rows of sutures. Two internal that would eventually dissolve and one really nice row on the outside that was super tight. The scar wasn't as bad as one would expect from such a wound.
So yeah, long story short: clean, stabilize, transport, let the ER deal with closing it up.