^^^^ I've always used 1/4" Hardie in 3'x5' (easy to handle & work with) secured with good thinset (Mapei) and screwed down ... lots of screws per Hardie ... about eleventy dozen... at least... it ain't moving

.
I always enjoy reading Greg's (and other pros here) posts .... if I ever have to redo a tile or hardwood floor, I'll use what I learn here ....
Thankfully I won't need to...
Hardie