I second this. Junkstore is really well integrated, I've installed so many forgotten Epic freebies on the Steamdeck because it's so much easier than going through KDE. I hope the GOG implementation comes soon.
I have a similar set up; Intel n100 but in an Aoostar R1 so allows for 2 x 3.5HDDs and dual ethernet ports. The n100 has brilliant performance for the price and power draw, so I'd recommend that to OP.
As a big fan of The Expanse and a proponent of GOG, I totally agree. I've never played any Owlcat games, but I'm still really looking forward to this.