If you add a comms specialist to your unit, you gain a comms upgrade slot for that unit. Is that comms upgrade slot lost when you lose your comms specialist?

Ex. I add an imperial comms specialist with a comms relay to a Stormtrooper unit. That unit takes a wound and I remove the imperial comms specialist. Can that unit no longer use the effects of the comms relay for the rest of the game?

I'm pretty sure that they can't be removed until it's literally just them and the unit leader (barring any line of sight situations)

14 minutes ago, zeromoon17 said:

If you add a comms specialist to your unit, you gain a comms upgrade slot for that unit. Is that comms upgrade slot lost when you lose your comms specialist?

Ex. I add an imperial comms specialist with a comms relay to a Stormtrooper unit. That unit takes a wound and I remove the imperial comms specialist. Can that unit no longer use the effects of the comms relay for the rest of the game?

No, you don't lose it even if the mini dies. That is because the adding of the upgrade slot happens only while building the army and there is no rule involving those icons during the battle.

2 minutes ago, KommanderKeldoth said:

I'm pretty sure that they can't be removed until it's literally just them and the unit leader (barring any line of sight situations)

You must be confusing with the droids, but they cannot be destroyed before other minis except the leader (unless of course line of sight situations) because they have the Noncombatant keyword. But as the coms technician doesn't have any keyword involving that, he is treated as any other mini in the unit except leader, so if you want you can make him die first.