David, jibs sheets should never get snarled in the safety netting. Either you are sheeting inboard of the lifelines, or you are sheeting OVER the lifelines outboard of them. You'd never run the sheets "though" the lifelines (between the lifelines and the toe rail) so there's no way for the sheets to get tangled in them.
OK, I'm sure there's SOME way but so far that's one tangle I've never seen or heard of. Don't worry about it.