Daft thought. But given that GNE are using StreetDecks on the X1 now including extensions to Dalton Park & Peterlee, could Arriva get away with StreetDecks on the X21/X22 if they decided to order in the future?

First thoughts, the StreetDecks were only a coincidential allocation given COVID and the need to keep the X30's / X70's out of Consett depot low height deckers using the originally ordered E400MMCs. But I haven't heard any bad reports about StreetDecks yet on the X1.