Would agree R-DOM is basically going to be impossible to source. In theory one could do it themselves, but you'd need a good bit of DOM powder to play around with. I don't think the tartaric acid process is particularly difficult, but working at micro scale is a skill in itself.You are going to have a hard time finding anyone who has enantiopure DOM. So your 2 x dose theory is false. 5 mg racemic DOM HCl from a direct source, matching melting point, were very much active for me. Albeit not what I was looking for, and not too intense for me personally.
Wish I had grams of DOM laying around.