sorry to report i can be of little help beyond offering up some slightly educated conjecture...
i have never seen the Tibetan tai chi set. there is a school in albaquerque that teaches it. i would hazard a guess that it actually might be this:
or not.
the Indonesian taichi is also of relatively unknown origin, at least to me. I dont rely practice teh taichi, rather i do the 'gung fu' end of the system. best i can say is that it is 'like' the gung fu, but done with taichi flavor/mechanics/techniques.
not a very substantial response to be sure, but it comes with the territory with my system. it is both a 'mixed' art, and fairly 'closed'. some styles have a history that is well documented. unfortunately, we have alot of gaps in the collective understanding of things.
the kung fu is pretty good, but the background is a bit murky.
regards.