I'd take each mesh count up to the manufacturers max recommended level, and they'll drop significantly from there depending on mesh brand. I have 4 different manufacturers mesh that I've been stretching lately and it's really cool to see which ones lose the most tension after the first stretch and which one's actually are "low elongation" like they claim. I stretched a few 305's the other day and brought them up to 30 newtons and came back an hour later and tightened the corner bolts and set it off to the side so it would relax a bit, and I was very surprised that a few hours later it had only lost about 2 newtons in tension. That's a low elongation mesh, and it wasn't one of the major manufacturer's mesh either, which was why I was as surprised as I was.