i'm not sure what causes that but i've noticed it on most of the palms i've cleaned or removed as well,as for blocking down i wouldn't push any bigger than 12" for the simple fact that since i pinched that nerve i've had a hard time lifting and climbing like i used to and remember use that bore wing cut,it works great.
If there is room maybe have someone on the ground pull the sections off the trunk to save fumbling around and to save time.