The verify function gets extremely low amount of traffic. Even on a production site. People don't log in very often. 

I like the purity that in production you shouldn't need to check configurations. But... Life isn't that easy. 
I think you should do the sanity checks always. That's after all where misconfigurations matter more. 

And I don't think we need to worry about performance loss since all it does is working with O(1) lookups and python string stuff. Uberfast anyway.