As one of the few people who actually thoroughly enjoyed Forspoken and has 100+ hours in it, going from that game to D4 felt rather jarring. Still does. As the game from a much bigger company, with a much larger budget and development time, I really expected it to have instant fast travel at release. Especially since they kept using the huge OW as a selling point...
Forspoken works on the Steam Deck, albeit with longer load times than PC or PS5. I think the DirectStorage feature is simply ignored if not supported by the system, so I wouldn't worry too much.