I'd prefer not to rely on other travellers to bring stuff as that would probably be a headache organising. Think I'm going to switch to 26 inch since I'm sure it'll be available, even if not in the exact model/width/tread that I'd prefer. 700c x 40 is too narrow.
I'll be honest, I think you're making a big mistake. Even if 26" tires are available on the route, they would generally be low-quality Chinese tires meant for locals riding short distances around cities, with little puncture protection or longevity. I talked to plenty of tourers and bikepackers last season who had to replace tires on route, and they generally ordered from Europe (oddly enough, SJS was said to have fast shipping to Tajikistan) or they arranged, like me, to have a tourer bring them when flying in.
And, as Andy says, 26" is regarded in the bike-travel industry as a dying format, and Schwalbe has already begun reducing its support for this size.
Choosing a rim based on weight, when you are already adding weight to the spoke count, might be risky. I’d go for reliability, and simply appreciate any small gram savings that might come compared to the Andra.
If you want a tubeless-ready rim as reliable as the Ryde Andra, then there is the Ryde Edge M 30 (which, however, does not come in 26", just 27.5"/650B and 700c). However, I'm not sure the Edge has the special drilling that Rohloff highly recommends. Rohloff’s FAQ mentions either the Ryde Andra rim which is not tubeless-ready, or (a company I hadn't heard of before) a
Rad15 rim which is tubeless-ready.