I have had the underslung ridgeline cause noticeable wear on PU coated nylon tarps. It did effect the waterproofness of that area. (occasional drips in heavy rain) Since, I've switched to using split ridgelines and pannel pull-outs, no more abrassion and the pannel pulls do a fine job in windy conditions.
"The more laws that are written, the more criminals are produced." - "The more laws and order are made prominent, the more thieves and robbers there will be." - Lao Tze
"Good people do not need laws to tell them to act responsibly, while bad people will find a way around the laws." -Plato
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