You do realize that we are in 2020, right?That's fine, because all the background stuff that's used by MacOS can use the HE cores. The the UI and frontmost app gets the four HP cores. Or at least that's how it should work.
You'd think, but on my 5,1 with Catalina there are at least three system processes that compete to get to 100%.You do realize that we are in 2020, right?