Well here at least, it has one useful effect even if a completely inactive alcohol was used, the act of making it a carbamate, seeing as how the intended route is through the corresponding isocyanate and alcohol, flame-drying one's flasks, distillation of the alcohol over calcium carbide. in a current of N2, Ar, He, etc passed through conc. H2SO4 (I don't consider this synthesis discussion, as I am merely talking of drying agents, not actual 'recipes') will result in it no longer being a ring substituted derivative of (alpha-Me)phenethylamine (in the case of whatever one might choose to make), but a derivative of the corresponding isocyanate (or indeed if one were to be cheeky, EtOH

)
Thus bypassing the misuse of drugs act in the UK, we do not have a US style analog law here, they do have widespreading bans on various classes of substance, but there are many things not covered, and nobody thought of this one before, when they wrote that steaming heap of shite.
Potency wise, bah, I am not so good when it comes to calculating actual weights from molar fractions, after having to convert the molar quantity in question in to a weight to begin with, I hate being dyscalculic, and besides, after a few shots of vodka, I am certainly not inclined to do it right now.
But I don't think its going to be an extremely significant dose of 2MTB at all, but the idea wasn't to get one pissed as a fart on the alcohol, but to smoothe the ride a bit by both the GABAergic effects of the alcohol in question, and by slowing release of the amine parent drug in the system, assuming formation of the alcohol in the acidic conditions of the stomach isn't damn quick anyway. If that is the case afterall, then its not a problem, seeing as how there would be little difference in speed of absorbtion to MDA in the first place!
But above all its about being able to keep as much of whatever one wants around at hand, without any illegality.
Potency wise, I wonder what the 1,1,1-trichloro-2-methyl-2-butanol derivative would be, given chloral hydrates large increase in potency over EtOH (and the fact that its rapidly metabolised to trichloroethanol, which I make the assumption, is the active drug, or certainly one of them.