Wood is more heat resistant than a strap wrench.  If you freeze the metal, then torch heat the stuck insert without heating the CW shaft, then clamp the hot threads in sacraficial (throw away) wood while gripping the CW shaft with the strap wrench, that might work better.  For better clamping, drill a hole in a sacraficial block of wood or plywood, and cut to the hole from one side.  You make a round clamp which will be more even than just squishing between two blocks of wood.  In the attached picture I'm using a hole "clamp" to get a much more flexible ring off an adapter.  This trick will be harder with the smaller diameter threaded insert, but it can help.