I've been using /execute as @e[type=brazier:crazed] run say hello when I get to the mansion to make sure I'm not missing them.

That's weird, they should instead of an evoked every now and than, but the chance surely should not be this low. I will give it a look

I did some testing and I always got about on crazed per mansion.
There is a new version containing an config option to modify the spawn chance, but I have also increased it by a bit.