Okay, I've followed all your advice and am in the process of recapturing all videos in 30FPS. For the wheels, I will remove all APNGs and compress the remaining PNGs.
It seemed very strange to me that I had to do all this while the table runs perfectly in 4K because, for me, playing a video should have required less resource than generating it in real-time, but you are right, on one side it's the CPU that works and on the other, it's the GPU, too bad for me
I tested with Pinup, and the result was the same, so I'm sticking with PinballX, which keeps your excellent PinballX Database Manager.
Thank you for your advice.