I am sorry to say this only now but I am worried about future maintenance of the code. So, if you agree with me and you have the time, please try to do those change before 1.6.0.
I know about the complexity. What I really want to do for some time is the following which dramatically reduces the complexity: Macros should be global, i.e. no scopes anymore. Scopes are there in TeX of course, but I don't think they are really essential for the usual user. This will make the code much much simpler.
I was waiting for Manuel Pégourié-Gonnard to update his xargs to implement the needed semantics for LyX. He sent me a snapshot, but didn't release it yet.
Stefan
