On the issue of palm swells for off hand shooting. First, the Blacktooth isn’t all that big and the trigger reach is relatively short so that even people with smallish hands can use it well. I don’t think most people who try this stock will have a problem with it, and I find it to be one of the better non-vertical grips out there. Second, for offhand shots, I personally find the gripping the rifle hard with the rear hand doesn’t promote great trigger control and accuracy so even a bigger palm swell wouldn’t bother me. YMMV.
On bedding, I didn’t watch the video or use the kit they sell. I bedded the recoil lug with the gray Devcon and it’s worked just fine. Mine is torqued to the spec which is 55#. It’s nicely free floated and I’ve had no issues with it.