No, you do not have to correct yourself, it is correct, what you stated is to the point. Working on it.
CIN/COUT/CERR is done and was easy. Trying to find a creative solution for UERR, that is not standard for C++ iostreams.
Basic Idea is to clone the handle from stdout to UERR. Possibly the other way around
May be as easy as moving the apl_init call up in the call chain.
Will report back on progress.