Tsk tsk. If you can't get through the front door, there's always a backdoor.
Workaround: instead of mapping the function ($A), map BC,f,u,n,c, ,$,A,XC This
works for me with a type {{8$a,A}} help frame with only {{0$D,$F,$N,$B}} (a few
basic types of help functions available) at the top of the help file.