yes but 4 spaces are covered by walls still,till an alien throw grenade inside
i think white-cat is talking bout x-com where craft was closed&safe before u opened door.
anyway there happened much times explosions and stun bomb worked inside closed craft even
that reaction fire is a bit trouble here anyway maps are little and u sometimes face full squad of aliens in visible range and youre opened to their RF.
As white-cat said harvester missions are easier so u have usually chance to take cover and use some tactic,crashed scout&fighters sometimes looks like lottery situations.
Maybe solution to make it more realistic will be adding crew casualties after crash and proper crew numbers scouts and fighters no take passangers usually .
Another thingy that can make situation more realistic,aliens from crashed ufo could have a bit less morale (bravery or whatever is called here that stat),u rather no often are super hero when u just crawled out from burning vessel:)