When I used an outside the tarp pole mod, I had to secure prussic loops on my ridgeline to house the poles and keep them in line and away from the tarp.
I personally didn't want any contact with the hammock from the outside and being anchored midway up the tarp. If something were to go wrong your tarps going to bear the brunt of it.
From the inside is different as the ends are usually a bit more secure and pose little risk of puncturing your tarp. Probably because they're longer.
I'd keep whatever you use pulled away from the outside of the tarp. I used prussiks on my pullouts so I could adjust the tension and not end up flattening out the top of the tarp.
"I ain't here for a long time, I'm here for a good time"
- George Strait