Hello,
I have noticed a good thing and a bad thing with the "Toggle custom push-pull" tool, or the option called "Replace native push-pull tool" in SubD preferences.
The good thing is that there is a significant performance improvement since version 2020, when this option is enabled. I'm just speculating, but this may be thanks to "PolygonMesh performance improvement for extensions", introduced in 2021.1 version. Anyway, it works completely smooth now, contrary to SU 2020 where I had to regretfully disable this option, because it worked unacceptably slow (32 GB RAM, Ryzen 3600, GTX 1070 on my board).
The bad thing is:
The latest SketchUp version has changed the way normals are handled when drawing faces. Formerly, we got normals facing down when drawing a rectangle on a floor. Now normals will face up, and extruding the face with native push-pull tool will flip the normal of the face, which is good and desired behaviour in most cases, because it will create a manifold box, with all normals facing out. I hope this behaviour will be ported into SubD, because now when I draw a face and extrude it with the "SubD push-pull", it will not get flipped, and we'll end up with non-manifold geometry.