Hi Georg,
The GoPro Hero 10 has a lot of in-camera stabilization in it. Which means it is not a 1-to-1 representation. (I have only an older GoPro, so my experience is not with a GoPro 10)
The procedure to create a lens profile is described here: https://help.maxon.net/c4d/2024/en-us/Default.htm#html/TOOLLENSDISTORTION.html?Highlight=lens profile.
Use only the data you get directly from the camera. No adjustments other than color.
The mask is an option to exclude moving objects, but it has no option to retrieve spatial information.
Tracker points will be created for contrast areas; if it does not match all other's movements, delete it.
Parallax is the "perspective" change in the image. The opposite would be footage from a lock-off (Tripod) footage, which doesn't provide data on the space. Also, just paned (and similar movements), and zoomed footage doesn't provide parallax. (Yes, I'm aware that GoPro has no zoom options)
Points that are manually tracked should sit on non-changing features. (I mentioned that in my YouTube link.
Camera Motion Tracking creates a 3D point representation of the stable world in front of it. Once solved, that "cloud" is static.
The idea of tracker points is triangulation. Lens distortion leads to variation in the speed at which these points move. This disables the precision of a stable triangle or leads to a useless result.
It is possible to track purely with manual points. However, if the footage and lens profile are not pristine, the rule that 8-12 tracker points will most likely not work.
With post-processing already in-camera processed material, you have two layers on top of problematic footage. In other words, the perfect camera/lens features are based on Global Shutter (not rolling shutter), while no stabilization is used, and the lens has minimal distortion. GoPro is not the camera for this work. Footage with no motion blur (and no added motion blur) is preferable for this work.
Since you mentioned After Effects, try to find the spatial camera path there, then merge that tracked camera in a Cineware file that allows you to get the result into Cinema 4D. (I haven't done it in a while, so this is brainstorming.
I'm sure that you went through this material, but I want to make sure you have the following:
https://www.cineversity.com/vidplaylist/motion_tracking_object_tracking_inside_cinema_4d/
All the best