Hi Doug, this is what I said over at the JB forum for two years, and now that I have tried it (albeit only once), it doesn't do it to an appreciable degree.
TLS says the floor has to be dead flat and the proper trowel used for full coverage. This is an adjustment from the way it was first marketed.
I don't think that air pocket concern is really an issue for me anymore. What is a problem is the loose thinset and the mess in the joints. When I try it again I will get some photos of the stuff going in so you guys can see more. For that first time, it was "all a-holes and elbows"
trying to get it to work and there wasn't any time to think about it too much.
I will say this: I think this has potential only in the hands of a top-notch tile setter that has a lot of experience. It is NOT well-suited for newbies, IMO.