We've looked at a number of FOSS and Commercial options for a project recently, and found most options were not much better than https://freemocap.org/ with video occlusions.

However, we did purchase the https://faceit-doc.readthedocs.io/en/latest/mocap_general/ commercial seats for Blender, and have found it workable with the results from the iPhone 3D camera App compared to other options (52 marker lip sync, gaze, and blink cycles will still need cleaned up to look less glitched in complex lighting.)

Combined with Auto-Rig Pro in Blender, it is fairly trivial re-targeting for Unreal Engine with volumetric preserving rigs (can avoid secondary transforms, so elbows don't fold in weird ways by default like Makehuman rigged assets.)

Best of luck, we concluded after dropping/donating a few grand into several dozen addon projects... there were still quite a few version rotted or broken add-ons for Blender around that people had zero interest in maintaining (some already made redundant by FOSS work etc.) However, there were also a few tools that were surprisingly spectacular... will still likely need to run both 3.6.x and 4.x ... YMMV =3