Thanks for all the great tips. I have always used my Maccat Ultra Tarp over the ridgeline. Honestly I haven't ever really noticed much rain runoff using kelty triptease lightline pulled REALLY taught. I like having the line to hang things and I always felt like it supported the tarp better and put less strain on the tie outs..
The only worry I've had was wondering if the ridgeline rubbing under the tarp at the seam would wear down the seam seal tape too quickly.