I have played for probably 50+ hours with this mod, and I have some feedback.

First and foremost: variants, overlords, and hidden tanks do not have any additional rewards for beating them.

There also aren't any settings to disable the innate fire resistance on overlord tanks, nor to limit the variant / overlord tanks after an encounter (though there is a setting like this for hidden tanks, which is curious).

Now onto the individual tanks themselves, some need little changes, some need big changes, I'll just go in order:

• Swift Tank: This tank is one of the more powerful common tanks, and could use a debuff to its health to compensate for the extra challenge.
  
• Boomer Tank: This one is more a performance issue than a balance issue, as the constant explosions are seemingly uncapped. I would throttle the explosions to be at fastest once every 0.1 seconds or something.
  
• Death Tank: This one just isn't very fun to face. I would change it to simply reduce the player to a grayed-out state on hit, rather than instant-death, which is still a terrifying tank to deal with.
  
• Spawner Tank: For a common tank, it would feel more right if it spawned a bunch of common infected, rather than piling on the special infected. I've never particularly had fun with this one in its current state.
  
• Reflector Tank: Conceptually, any tank that requires the bots to stop shooting is going to be a problem. Player bots just don't know how to handle these.
  
• Immortal Tank: Same problems as above, remove the timer or rework it.
  
• Necromancer Tank: Same problems as above.
  
• Trickster Tank: Same problems as above, also can kill many campaigns. Not a fun tank both in concept and practice.
  
• Admin Tank: The lowered speed command can kill a campaign and does not add to the fun of the tank.
  
• Thief Tank: Removing items entirely is not a fun mechanic, dropping them is ok though.
  
• Binder Tank: Runs into the bot issue seen in many of the above tanks, and is literally impossible to kill in certain scenarios.
  
• Fortress Tank: Should probably run a check that players even have moltovs, otherwise this tank is unfair in certain campaigns.
  
• Void Tank: Same problems as death tank.
  
• Samsara Tank: Not a fun tank since it's just a bullet sponge, also impossible to kill in certain campaigns due to limited ammunition.
  
• Jester Tank: Swapping primary weapons is not a good mechanic.
  
• Purloiner Tank: Same issues as thief tank.
  
• Voidwalker Tank: I have not been able to find a way to kill this tank, it is too hard to hit, which consequently makes it unfun. A small cooldown to the teleporting would fix this.
  
• Aegisbreaker Tank: Soime fun mechanics here, but is mostly just another bullet sponge.
  
• Gravecaller Tank: Same issues as necromancer tank.
  
• Eternaldread Tank: Same issues as immortal tank.
  
• Mirrorbane Tank: Same issues as above.

Tanks I didn't mention are in a decent shape, but these are the biggest unfun tanks right now. The ones that have negative effects on shooting them or nearby infected should either be reworked, or have a special case in the script that excludes their negative effects when a bot shoots them. Given that most players are going to play with bots, this is a big priority.

(Don't forget the things I mentioned at the top of the page, and thank you overall for a great mod.)