With flood fight getting all the love and no default way to fight against new elite enemies, I’ve done it myself.
I put together an Elite Firefight as best as the options allowed. I swapped out all Brute, Brute packs, and hunter groups with their elite equivalent. I left Brute chieftains, brute airborne, and spec ops as there isn’t any good boss/ special class equal. All vehicles still spawn with brute pilots, no way to change that I believe.
Heretics were a non-starter as they fight the covies as well, so I couldn’t use them to fill in elite gaps. It’s a firefight classic variant if y’all want to try it, it’s on my file share, GT: Greviator.
Side note, I hope they continue to add things this update has been amazing. I’d love to see some zealot sword carriers or ultras with fuel rods!