Heavy stun bar is annoying and players don't have any tools to interact with it.

First of all, the fact that Heavy stun bar doesn't cleanse after getting Heavy stunned is stupid, it's the same as if you got frozen and after you get 100% debuff to get frozen again, you already got punished by getting, well, stunned. It's a christmas miracle to stay alive after getting stunned anyway and while you can argue that it increases your uptime of active blocking by being able to instantly blocking again, I would argue , why the heck not ? It's not like you get anything close to being immortal like this, you will most likely die when you get stunned the firts time anyway and if you don't, enemies defenetely surrounded you, so active block won't even block all hits anyway.

But sure, let's assume clensing Stun bar after getting stunned is non-negotiable for some reason, then players need to have tools to interact with it. There are currently precisely 2 notables which interact with Heavy stun bar and 1 of those is Parry exclusive. It leaves warriors who want to, oh I don't know, specialise their build in an RPG, towards active block, there is ONE NOTABLE AND THAT'S IT. Where are mechanical interactions with active block ? Item modifiers? Gems? Persistent buffs? Keystones? Why don't we have a support to cleanse part of your Stun Bar when you Heavy stun someone, why can't I make my Stun bar smaller, but regenerate much faster, maybe drop active block effectivenes but make getting heavy stunned harder?

If you make a core mechaninc there should be some interaction which players can engage in it. Curently there is none.

The worst part is that there is technically an interaction avaliable to you. And that's to not fight and afk for a couple of seconds whenever you get close to being Heavy stunned, and that is the worst interaction you can have in an ARPG. Not only it slows your progress to a crwal, it just feels like shite to have to activelly make a decision, I am not going to do anything for 2-3 seconds and look at my bar, waiting for it to deplete.

As far as I know the stun bar will drain if you are not actively holding the shield up and stun threshold makes it harder for you to be stunned. Maybe get more threshold on your gear and passive tree or you know, don't hold the block button constantly lol. Honestly don't know what to tell you. A friend of mine plays a totem build with his warrior and only brings the shield up to bash for a little more dps here and there.

Sure you can get more threhold, but that's the same as telling a caster who has troubles sustaning mana, just get more maximum mana and when you run out, stop casting for a bit. Sure, it is an answer, but it really isn't.