I did a test last week-end and the auto alignment seems to have corrected one side more than the other as seen in this capture (asymmetry of the resulting center and more unwrap to the left side). I tried manually choosing points but the result was not ok.
It’s probably more complicated but in my situation the sun was completely to the left so the exposure of both camera was not the same but it’s probably difficult to match in post.
The right side is slightly larger, but it is hardly noticeable.
It may depend on the frame that you chose to stitch. I always choose a frame right before the kickoff, when most players are stationary and a few are near the camera to provide good stitching points.
As for the exposure issue, I usually enable the spot metering mode and point both cameras to the same spot on the field before recording. This doesn’t completely eliminate the exposure difference but it does make the final video much better.
The symmetry is much better, I’ll try for the future as you said to chose frames close to the kickoff. I’ll check the options to specify the frame to use for stitching.
For the exposure it’s not a big deal as this match was really the worst with the sun completely perpendicular and just over the horizon.
I have the same problem with exposure and fixed it by combining the GoPro files in DaVinci Resolve (free program), if your files are 4K or less. The software looks complicated but if you watch some YouTube videos on what you are trying to do, it’s pretty easy. Once you have the left and right cameras looking better than stich the files. I will try you videos out so you can compare.