This may have been raised in the past, but after the release of SoTT it may be worth revisiting.
In high pressure settings, tagging a Ratling or Globadier sitting behind hordes/ armor is very useful for communicating threats or assisting snipers in firing.
Currently, it is very easy to mis-tag a Stormvermin instead of the Hookrat behind them, subsequently leaving your tag on cooldown.
I would be suggesting a mechanic similar to the Deepwood Staff alternate targeting, where holding the tag button would highlight enemies and releasing it would mark. Maybe some user customizable priority would be nice (if specials and elites are in the same line, specials get tagged first or vice-versa)
Of course, social wheel would need to get re-binded and there may be other considerations I am not aware of.
On a side note, adding on to this, how about buffing items/ debuffs to enemies by channeling the mark for a period of time? Could be talent or passive based. I feel like this was being considered going off some of the names of the talents (OE’s Spotter passive comes to mind) but I just wanted to share my suggestions for a nice game and community that has been very entertaining thus far