That is how I do it when the ridgeline is exposed. You can get the UQ to lay asym by using 2 loops on each end spaced a couple inches apart.Without a bug net, the prussik has real possibilities! I can't think of any negatives.
I also use a non load bearing external ridgeline on my WBBB when using a full length quilt. Just works better for me with the infinite adjustment points and upward pull.
Those triangle things are great when used with internal ridgeline hammocks with bugnets. Not that I am biased are anything