While I’d like to see more missions using environments that aren’t used much, I mainly want to see every empty counter have at least one mission attached to it so I can do random loops around a planet; playing missions until I’m too tired or too bored.
Other than that, I like missions that force a split in the party. Something with two or three paths that need to all be completed for an S-Rank. It doesn’t even have to be only beatable as a party, unless you want max reward.