I searched Bitbucket and this forum, but I cannot find “the Problem” you say you reported and I claim I fixed, unless you were talking about "no error appearing when closing the .InitializeFunctions procedure? Is that it? My reply was that that was expected behavior, runtime errors are only reported at runtime.
Perhaps there is something else you are referring to. There are no unpublished fixes in this area of the code, except that in my unpublished version RegisterFunction now works in addition to RegisterCustomFunction.