Cyborg teleporter upgrade works when stunned.

[Clarks]

The borg teleporter doesn't leave a blue portal for me to follow a borg through and keep hammering or forcing it to spend all its energy.
They can just get away, scream that you are a bad guy, and come back in a few minutes.

And there is no time to debrain them before they teleport somewhere else.

It's true that teleporting borgs don't happen often, but they have enough of an advantage already.