"Maybe the Windmaster is equivalent to adding that windscreen to the OD-1R. How does that work in the wind?"
Pretty good overall. It's been almost a year since I tested it with/without the windscreen but I found an increase in fuel efficiency when I used it even with no wind. Not enough data to compare so it's just anecdotal but good enough for my purposes. It's possible that my fuel savings with the windscreen doesn't justify the added weight; I don't use canister stoves all that often so I haven't been all that motivated to run any more tests to make that determination. For its intended purpose, the windscreen really helps in the wind.
Putting the windscreen on the ODR1 is a bit kludgy. Not a big deal but you have to juggle it while bringing the pot stand arms up. I like to keep my canister and stove in my SP700 pot but the windscreen adds enough that the lid doesn't sit on it properly. That has become a non-issue for me as I've thrown the lid away and have replaced it with foil.
The small stand for the wind master has a clip (visible in the picture you shared) on it so I'm wondering if it will fold in half?