Noticed this is in the standard game (non DEV version) as well.

Without PiP 108 FPS, with PiP 55 FPS. Thats over 50 FPS cut. Tested outside of a town. Inside towns it get much worse, and thats with all PiP settings. No difference in FPS between LOW or ULTRA PiP settings.

Please bring back earlier PiP low FPS consumption on the lower settings, and have this new faster framerate PiP on higher settings.

I never had to turn PiP off before, and it seems there shouldnt be a reason to since it worked perfectly fine before. Please consider this so most people can enjoy this new function in ARMA.

EDIT:
If its any help i know what would work really well. Instead of lowering the amount of things you see in PiP (the FPS difference is minimal between low and ultra visual objects) just lower the framerate on the lower settings and i think it will work perfectly.

PiP settings:
LOW = lower framerate plus standard setting "visual objects"
STANDARD = lower framerate plus high settings "visual objects"
HIGH = higher framerate and standard "visual objects"
ULTRA = higher framerate and maximum "visual objects"

Since you had the lower framerate earlier which worked perfectly im sure you can do the above and get more people happy.