It's only problematic because of gridcamping. A guy coming down that elevator has basically zero chance to survive.
Personally i'm fine with people gridcamping places of value aka the so that they can control one of two areas to get chemical components.
There is a fairly simple answer, get two dogs or other melee NPCs. give them two sticks of ticking TNT.Go down to the camped area, let the Mercs charge at the enemy mercs, you and the mercs die, but the others get blown to pieces by the TNT.
Or. just make the mercs run out of bullets. they will run out if you make them shoot you over and over, than just take a SMG down and waste them.
One merc per Character!!!
What part of "not being able to fight back because you just got instakilled" are you personally fine with?
The part where you could fight mercs with mercs or the part where some rather large gang will eventually clear it out. The fact of the matter is someone blocking toxic caves and making chemical components harder to get is a great feature especially if you make drugs and jack up said prices.
Looks like we got variance when it comes to encountering dangers. I personally prefer having a chance to retaliate when under attack, not running around head first and get over things with trial and error (meet something, die, come back, die again, repeat until success).