Is ldapdb an auxprop plugin?

I need to provide a libsasl2 package that lets sysadmins decide how they 
want to configure
sasl at runtime.

For mech plugins, it appears that I can get an application to ignore an 
installed plugin using
mech_list:

But for auxprop plugins, I do not seem able to force ignoring the ldapdb 
plugin using
auxprop_plugin:   or canon_user_plugin:

What am I doing wrong?

Thanks in advance for any help.