I have posted this photo in the past. The Cottonwood made me a believer... I always wondered what it would feel like to have a spar split. More like explode.
Anyhow, in this photo, I am tied into the neighboring tree - after it split. I had set this other line after having a funny feeling and hearing all sorts of cracking & popping (while chunking down the spar). I continued to make my cuts while swung over on my climbing line.
My routine is to set my climbing line around spar, snug up with a blakes. Move down for each cut, along with my steel core lanyard. Keep meaning to switch to an adjustable friction saver - for faster escape action. Maybe I will finally order up the parts...