I assume that CC here stands for Crowd Control. I have to specify this since I am not sure to understand the point here.
The Crowd Control abilities in most games I have played so far are precisely to deal with… crowds, ie masses of regular enemies. They are most of the time pretty much the opposite of the abilities dedicated to bosses as far as I understood, which is why I am a bit confused by the approach of that discussion. In the old D2 days, there were the duellists, strong in 1v1s and weak in 1v+s, and the massists, weak in 1v1s and strong in 1v+s. This was all clean and clear and ready to go. Now confusion appears to be the new rule.
But if by CC we are talking here about abilities affecting the enemy’s behavior, then this makes more sense, but I would then suggest to change the term to something clearer like AI-affecting abilities or something like that.
I have no problem with game mechanics with abilities with different purposes: if it is clear enough, this provides the player with different options, which is usually good. But now we have that Blade Trap that some say provides little value against the monsters that are going to be dealt with anyway, and no value against the big ones where it could actually really shine. I am under the impression that there may be a misunderstanding here: the developers disabled its effects on the bosses because they fear the entrapment abuse, while the players may miss it more for its actual defense reduction debuff. If this is the current situation, I fear that this is probably not going anywhere, since enabling a part of the ability features and not another is not going to make much sense at the end.
The problem with most of those debuff skills is that there is no equivalent for the bosses: there could be AoE versions and single-targets ones, with AoE being effective against masses and 1v1 skills effective against bosses, but Grim Dawn is so much into putting a bit of every effects into every abilities that it ends up paying the price: some confusion with what is supposed to do what exactly and nothing really doing something much different than something else.
Everything can be fixed, and especially those things that we have ourselves broken. It is just a matter of willpower and creativity. This is what is for that organ that nature has put in our skulls.
But before stating what the skill should be, we have to make sure first that we really understand what it was supposed to be in the first place: I am personally not sure that that skill has ever been designed to be dedicated to bosses. Yes, it was first a single target skill I think, and since it features entrapment and defense reduction, makes it a right candidate against bosses, but since the skill has then switched to that mass entrapment function, I am no longer sure. To me at the moment it is mostly relevant in corridors, when the enemies arrive in lines, and you want to hinder their course by preparing your more efficient attacks, and that’s it. Not much more.
The only way to have this balanced is to have it back to a single target ability. If it can entrap everything in the game, and especially with such low cooldown and with piercing damages, it turn obsolete at least the half of the other abilities in the game. Everybody go NB > BT and trap trap trap trap trap trap his way up to the final boss.
No. Hence my suggestion to either have it AoE persistent to make it a good option against masses at choke points, or have it a 1v1 ability effective on 1 target at most at any time with low range and average cooldown and effective against the bosses. I can’t see any other way to have this more balanced, unless the ability is completely reworked to something else. I think that what makes that skill so hard to manage is its entrapment function. Maybe it should be switched with a more usual slow effect. Entrapment should be restricted to skills really not doing anything else, like the net. The entrapment+damage is a very sensitive mix in game design.
Sorry for the long post. I hope that this makes some sense.