I've tried a couple toasted almond orgeats and while I think they are lovely, I'm still on the fence about whether they are appropriate for all applications.
As you mention, for brown liquor drinks, sure.
But for Gin or Absinthe drinks, not so much.
I recently made a batch of pumpkin seed orgeat/horchata where I toasted them and thought it added a great flavor. But then, there's no real historical precedent for how a pumpkin seed orgeat should taste.
Made some toasted orgeat this weekend after reading this thread and while I absolutely love it, maybe more so than the first batch I made using non-toasted blanched almonds, I would agree that the toasted version may not work in all scenarios. I found toasting the almonds brought out a bit of a salted peanut-type flavor in the final product which might be a little off-putting with gin-based drinks.
That being said, I just read something over on the Alcademics blog about a drink with Castries peanut liquor and Beefeater 24 that he claims is pretty good (I'd probably need to be convinced, but I'll take his word for now). I'm not saying orgeat and Castries are the same thing by any stretch but given the flavors coming out of my batch of toasted almond orgeat maybe it's not that much of a stretch to say it could work with gin. Guess there's always one way to find out ...