For me it's quite to opposite. I get decent FPS while outside, in the VC my fps are "ok-ish". But I get heavy FPS drops while panning around the VC with Chaseplane. Every time I move around the camera the FPS drops down to 5-10 FPS. After I stop moving the FPS get back to normal.
I haven't changed any settings after installing the 767. With all other addons (I have all airliners for P3D) I get consistent 30 FPS in the VC. Even in heavy scenarios like during approach into KFJK or EGLL. My specs: i7-8700k (5.1Ghz OC), GTX 1080Ti and 32GB Ram.

Also the VC lighting system seems to be buggy. When I turn on the Overhead Lights all other panel lights switch on too. When I switch on the panel lights -> the overhead lights turn on. Is this how it should work or is this a bug?