I was looking for this feature while trying to clean up some of my tabs today, and was surprised to find it doesn't already exist! All this time I thought for sure a tab group feature must have been implemented, as even Safari and Chrome have it. Hop...
I also support this idea and have been looking for such capability for a long time. OP made a great presentation on the scenarios where this would be useful. As another person stated, Safari browser supports the closing of synced tabs from other devi...