How to use mattress pads and toppers

My mattress encasement encases only the mattress, and it is sealed with the Protect-a-Bed locked zipper system from a previous bed bug experience. I use the mattress pad for a bit of softness and to have something that’s easily washable covering my foam topper.

However, two of your statements

seems to contradict what you said about toppers in Post #10 here (emphasis mine):

Wouldn’t having both a topper cover and a mattress protector on top of it be redundant? It seems like the mattress protector would serve the same purpose as the topper cover.

Thanks much.