Summary
Cauley-Stein's value primarily comes at the offensive end, where he is a legitimate lob threat either out of pick-and-roll or hanging out in the dunker spot. His size and athleticism at times provided a real benefit for the Mavs, but it was somewhat superfluous with what Dwight Powell brought to the table, and when Marquese Chriss overtook his spot in the rotation, the Mavs chose to move on from Cauley-Stein.

On defense, Cauley-Stein has a decent block rate, but isn't considered a good rim protector. He hasn't developed the positional awareness to make a real impact on defense, which is the reason he hasn't fully lived up to the expectations some had when he was drafted #6 overall in 2015.

Cauley-Stein can be a decent third center, but I would not give him more than the minimum. However, I have said that for multiple years and he has proven me wrong, but I think the minimum is most likely considering he didn't sign with another team after being waived by Dallas.
 
Cap Considerations
Cauley-Stein was waived by the Mavericks during the '21-'22 season, and didn't finish the season on a roster.

Teams will have multiple ways to sign Cauley-Stein as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, or even the Room MLE or Bi-Annual Exception to sign him. It's also likely that Cauley-Stein only gets minimum offers, and may not even get fully-guaranteed offers.