I have a question. I hope one of you knows the answer. I've noted some issues with the frame rate while converting the NTSC GOUT (29.97fps, 23.976 after conversion) with Handbrake that I didn't seem to have when I converted the PAL GOUT (25fps). Now, I'm a bit confused. Should I use constant or variable frame rate in the conversion for the PAL and NTSC GOUT?

Update:

As far as I understand it PAL uses either 25fps or 50fps (interlaced). So always multiples of 25. NTSC uses 23.976fps or 29.97fps (interlaced). However, it can also be a combination of both if film footage is combined with video, leading to the variable frame rate.