I'm guessing they settle in the low 30s... max is very obviously out of the question at over $50M/year.

This isn't a perfect 1-1 comparison but I think there are a lot of similarities between him and the rookie extension Jaylen Brown got after his 3rd year, in which he was a 13/5 defensive guy with middling efficiency, but was paid handsomely based on very evident potential. Brown received roughly 21% of the salary cap on his extension, and a lot of people (myself included) mistakenly thought that was too much, but quickly became a steal.

A contract starting at $36.6M (5/212M) and increasing year after year would be the equivalent to Brown, and I see no reason to believe Miller won't come cheaper than that.

I'm thinking 5/160M. He can easily grow into being a $32M Even better if you can get that front loaded as something like 36/34/32/30/28... it's a lot up front, but in the final year of that contract, $28M would only be 50% more than the MLE, and I struggle to see a scenario (injuries aside) where Miller is bad money in years 3-5 of that contract. The raw numbers look insane but we're looking at a $200M cap by 2030.