A bunch of Hilton family hotels don't feature Digital Keys yet AFAIK. (Can they feature them if they still use slide-in magnetic-strip keys? or do they have to have switched to contactless keys for Digital Key to work?)

So the simple solution is to pretend for a moment there isn't such a thing as Digital Key. Go to the check-in desk and get "real" keys for the room; they'll come in a packet conveniently reminding you what room you have! If the hotel does indeed support Digital Keys, you can then use that "real" key packet as nothing more than a written reminder of the room number, if you wish.

Ie, while it may nice to skip the front desk if you have all the information you need (and they have the information they need), is it so terrible to stop by the front desk if you forgot some piece of information you need (that they have)?