I am not sure this is what you are looking for, but here are a few studies from the PubMed site that look at ALA and glucose metabolism:
These studies seem to be looking at the therapeutic benefits of ongoing ALA supplementation to enhance glucose metabolism, as opposed to minimizing the insulin spike that might occur from one (carb rich?) meal, but the effect might be the same.
I take ALA regularly and I sometimes also use it in the manner you outlined. I, too, have wondered whether it has the potential to significant blunt a one-time insulin spike.
The Linus Pauling Institute also has some good info on ALA:
Great question... I hope this helps.