At THIS point, I think it's straight foolish to not tank. What's amazing to me is that The Zone people are openly advocating for it... so I don't know, maybe the organization at some point will do the sensible thing.
A cheap, highly valuable asset is awesome anyway you slice it. You walk into 2019 with a playoff run, a very young superstar, the best defensive anchor in the world, a very nice glue guy, Quin Snyder, a very good organizational reputation, enough cap space for one or two max free agents, AND a blue-chip prospect... yeah, I don't know. Go big. Make a case to Klay and Butler, have the assets to do an extend-and-trade for Porzingis if that situation doesn't improve (a la Harden). Hell, you could get Mirotic plus one of those other guys (and not use any assets to acquire him now)! And you'd probably still be in prime position to grab Porzingis if he followed through with his threat of taking the QO and going into 2020 as a UFA.
Again, let's go big here. Time for the Jazz to try an unprecedented approach for them, because they are in kind of an unprecedented position (having an explosive, well-liked, incredibly respected franchise player as a rookie, plus everything else [I think players would like to play for Quin more than players wanted to for Sloan]).