Simply stopping and removing that order would be sufficient. The last thing I would want is way more alert messages and interruptions. Just the one when the fleet is full.
I think they should stop salvage when cargo is full. Then give a warning. Also conditional orders should allow salvagers to dump off cargo then return.
Just salvaged two 30k wrecks and one 9k wreck with full cargo spaces Would be really good if salvage fleets throw you a warning when they get close to a certain amount of cargo space. Something like "<Fleet name> cargo space is nearly full"