Changes characters, No Action

I installed this and used the test URL extension ?fcc=demo-on and it put up the message at the top but there was no actual slow down. Caching?

More importantly there is a bug in this plugin such that with it installed the TM trademark symbol ? (option-2 on my Mac keyboard) turns into a weird string of characters. Deactivating this plugin restores the trademark symbol. Rather odd.

https://www.ads-software.com/plugins/fcc-slow-lane/