that has nothing to do with metric vs imperial:

“Lumber manufacturers typically cut a tree into the various standard types of dimensional lumber very shortly after the tree is felled. At this point, the 2 x 4 is actually 2 inches x 4 inches, a 2 x 10 is actually 2 inches x 10 inches, etc. But then the newly-sawn (but soaking wet) lumber is then kiln-dried until it reaches the desired moisture level. During this process, it shrinks as the moisture in the wood is removed and the wood cells shrink. Once the drying is complete, the boards are then planed to a standard size. Hence, what started out as a 2 x 4 now measures 1 1/2 inches x 3 1/2 inches.”

https://www.thesprucecrafts.com/why-isnt-a-2x4-a-2x4-3970461

don’t know why you’d want to? you may trust your dns server but without dns over https the dns requests themselves are sent plaintext and are vulnerable to man-in-the-middle attack. with dns over https the dns requests are encrypted and that encryption would have to be broken for a MITM attacker to see your requests. more security is better and dns over https costs virtually nothing to use in terms of cpu resources.

edit: oh do you mean whole system mullvad VPN? if so, then yeah dns over https doesn’t really help much but it’s also still a case of why bother turning it off when there’s no benefit to it.