Hello proposed an update to TWThreat so it could broadcast your target's threat to every raid member, would be very usefull for packs of multiple mobs so you could follow what's your threat on each.
By default TWThreat has threat percentage on frames so you could probably just enable it for this, but this would also be the base to make new addons so you could have threat integrated with a lot of targets (always needs someone targetting that mob to share it with the others).
https://github.com/octo-addons/TWThreat/pull/1