I never have that problem since I never get my line caught in the trees or on anything else. I am the most compentent caster, fisherman, wader, rower etc. so I have never thought about about it. LoL
I have never snagged anything that I have had to find away to break my mainline. The only times I have been snagged on something I was able to get it undone my snapping my leader.
Ryan