Enhanced Security Questions

I am looking for some additional info on Enhanced Security. I have searched the forums and checked documentation, but I can’t really find much about it. The basic info I was able to find states that Enhanced Security enables TLS 1.2 and SHA 256. My first question is, what all needs to be done to enable Enhanced Security besides just pressing the button? The environment is all version 9.2 and consists of two top level relays, a large amount of smaller remote relays and then the clients. I assume that the TLS change affects the communication between the clients and relays as well as the relays and server? Does the change also affect fixlet file transfers (prefetch http://server:52311/uploads/…) or will those still go over http? Once Enhanced Security is enabled, does it cut off http communication and if so would that prevent a system that was offline at the time of change from communicating once it came back online?

I appreciate any info or tips you all may have.