Thu-hiker Pertex

Haven't tried it for MYOG but I have the OR Helium II (shield+, better breathability but similar) and a down jacket with endurance that work well.

Shield is basically just a PU coated waterproof/"breathable" fabric. It's pretty nice for what it is, but it's not an event, neoshell, or even a gore-tex. Also Thru-hiker doesn't mention the construction of their particular fabric which is annoying. See if you can contact them to find out if it's 2, 2.5, or 3 layer. If 2 it will need a liner (adding to the weight). If 2.5 it'll have the tiny plastic dots glued in and 3L will be fairly robust for weight.

Endurance is basically the same thing, with just a thinner membrane. It's a weird fabric and probably has only niche application. Doesn't breath great but incredibly water resistance. I haven't used it too much since it's only a huge a down puffy for deep cold. It will be virtually wind proof and mostly waterproof (with the expected low breathability). Makes a nice outer for belay insulation pieces where you're just standing around. It would be terrible for anything you're going to move around in. Consider it a poor man's low tech version of EPIC. Off the top of my head it may be ok gaiters, gloves, and maybe even winter only single wall shelters. Roger probably has something to say about that, which I'd listen to.