I didn't ask, but given the Netflix tech blog post on this item I'd imagine your idea is in the ballpark
This is an almost inconceivably expensive solution, though. As if encoding AV1 isn't bad enough already, let's go ahead and do each representation 5 times! Multiply that by however many representations you want to provide and the necessary compute resources are astronomical, even just doing SD content!
In my test last night at q55 I got quite good results at just over 500 Kbps.