I’ve been thinking about this subject a whole lot and there is many way to approach the problem, but i think we need to agree with the initial problem first so let me state it IMO: “Light armor is best for damage, mobility and survival due to a combination of armor weight bonuses, light dodge and perks”
I believe this can be tackled by multiples means. But if we assume that the mobility and damage are not the biggest problem here (Light>Medium>Heavy for both) then the problem is clearly in the last one, survivability.
I would suggest to address it to modify 2 things, first the armor values, second the absorption system.
Currently between gems, consumables and fortify you can get light armor taking absolutely no damage when getting hit and when combined with the healing that is in the game it makes them impossible to kill if you ever manage to catch them.
My proposal for the absorption system would be to modify it to be working as an increase to the armor value for that type of damage, so it would scale with current armor. Meaning fortify would not give you 10% damage absorption but increase your armor effectiveness by X% ( X to be defined for balance).
I would similarly make it so that more healing is tied a bit more to %health gain, less flat amounts to make it more efficient for high health pool characters so that when a light armor players glass canon DPS/Healer get’s caught out they feel it.