I only play Skeld but:
Lights are good, unless the lobby's settings are retarded.
Reactor can be good when you're on the right side of the ship.
In contrast, O2 is not very good when you are on the left side of the ship.
Comms are never good for hiding bodies. It can get people off of cams and the admin panel, but reactor and O2 will (respectively) do that as well.
Reactor and O2 are both good for letting bodies go stale.
Lights are less effective here, but they can distance you from the body.
For most players in the round the only effect of comms is locking the button so it is a low priority fix. Comms will not help you with dead bodies.
Comms does not seem to have much use outside of faking tasks in lobbies where the bar always updates.
The only fun time to for sabotage comms is it at the start of the round when nobody has read their tasks yet.