[Mailman-Developers] Answering my own question

[Dan Mick]

Adding a "save_list=0" (or just a fourth argument '0') to the two calls
to SetUserOption in admin.py speeds up that "set one option" flag a
*whole* lot.  It might be that similar "optimizations" to the other
forms processing (DeleteMember, primarily) are a bit unsafe, but it seems
like a huge win for the SetUserOption calls, and not very unsafe, since
the list will be saved after processing all users anyway.