This final Dominic was tight and the timing on his groundgame was way off the first few sets. I never felt Theim was actually humming at his A game for any sustained period of time. ( compare with the AO)
Theim has made 2 HC Major finals winning one ( could have won the other but I digress) , nearly squeaked through the YE ATP finals on indoor low bouncing HC , won a Master on HC over Fed, and has HC victories versus Nadal, Djokovic, Tsitspas, Zverev, Medvedev, etc.
So despite starting as primarily a natural clay courter, he’s made the adjustment for HC though I still feel it’s not quite a natural fit. Like Nadal, with hard work and a strong drive he’s willed himself into a great HC player.
With grass it’s an open question per the issues Sundaymorning brought up, but if anything Dominic has shown he’s willing to do what is needed to improve.