2.3 for 4k and 2.0 for everything else
There are PAL and NTSC specific versions of the camera. If you purchase the camera from a store in a PAL region then you will have 25fps while in an NTSC region you will have 30fps. The camera cannot switch between the two.
From what i can tell panasonic cameras apply lens correction to the raw image files to correct for distortions inherent to specific panasonic lenses. Does this correction get applied to 4k video footage before compression as well?