Everyone wants medium and heavy armor to be relevant. I’ve seen some good suggestions about adding a blocking specific bar that scales with armor type.
One reason light armor gets just as tanky though is fortify. The game is heavily dependent on the play between fortify and rend.
So a simple fix here is to scale all sources (abilities / perks) of fortify according to your armor type. This combined with the roll distance changes after hit that they are adding will make light armor feel squishy which is exactly what it should be.
I think it would fix everything with a small change personally
It would fix all the complaints about killing healers too. Most of the blame people put on rapier without realizing the healer is fortify capped. I only take time to riposte if there is 1 smart person applying rend or disease