MusicallyInspired (Brandon Blume) mentioned this to me. Space Quest V "allows you to skip the crest-cleaning sequence when playing with the EGA driver."

To enable EGA, go into "resource.cfg" and change the video driver from "VGA320.DRV" to "EGA640.DRV".

The cleaning sequence in QuanVM only takes a couple of seconds, so this doesn't really save that much time. Also, to my understanding, this only works in DOSBox. However, DOSBox max cycles is still pretty zippy, and this may be worth looking into.

Via sluicebox, a way to skip picking up the fuse from the toolbox:

you don't need the toolbox fuse! ignore it and just pull the two middle fuses and put the good one in the broken socket. the two fuses from each column are the same size and swappable. i think the diagram is trying to convey this. the socket beneath the broken one is "Cockpit Glazing Blemish Removers", suggesting it's unimportant. so yeah just use that. cliffy's fuse is superfluous! the game tracks if you've done this so that it can correctly restore the screen, but it's the end of the game so you can never see this.

Not sure if this would save any appreciable time, but worth testing.

Also from sluicebox, here's a way to cheat at Battle Cruiser (only helpful for 100%):

https://www.benshoof.org/blog/space-quest-v-battle-cruiser-cheat