Setting to replace core's Permissions page doesn't work

Hello! Great to find a module that succeeds in speeding up a permissions page for a site of ours with some 4,000 permissions across 11 different roles.

That said, while I saw the option in this module's settings form to allow it to take over the Permissions page, that doesn't appear to do anything. Looking at the code of the module, I don't see that replace_core is called anywhere outside of the settings form itself. (At a quick glance, I believe the same is also true of auto_expand_search, by the way.)

It'd be great to have that functionality working so we can get our Permissions page moving more quickly. Thanks!