I know its hard for you devs to find a consistent reply here.
It is hard to reproduce.

I either get the framedrop, critical error, or framedrop + CE. Guess its releated.

With hotfix RC patch, the framedrop is still persistent for me (but not that often).
2 frames at none or very low object models.
Different KOTH server.
View distance however is 3000 (also for objects).
The framedrop occures more often when the view distance is set higher than standard (KOTH v9)

Arma3Test148RC
http://youtu.be/2OPolzxlPDY

Yes 1st person too. I can snipe with scope in two different magnifications. I use the lower to make out enemies (towers are not visible sometimes but players always) then zoom and shoot through. Pretty weak and no fun actually, but it works..

FPS drop and memory issue: https://www.youtube.com/watch?v=t2vw5AyP8iM