I have multiple dream rando bikes, but that's a different issue. I definitely want a disc rando with larger tires, because my gravel bike keeps getting switched to that duty and then it's a pain to switch it back for gravel duty.
I modified a Lezyne pump to fit on the seat stay (as is the custom now with framebuilders).
I would go tubeless on anything over 38mm. I am not convinced about tubeless on smaller tires.
I think a front rando rack is worth having. Rando front bag is the best improvement for me since dynohubs. That means the headlight has to be mounted on the rack. Adds a bit of complication for the wiring
I like 2x. Going to get a Shimano GRX crank, I think. OTOH, the gravel bike might be going to 1x
I have 2 chain hangers on my travel bike. One is a Columbine Qwikchanger, and the other is a Rinko style chain hanger up on the drive side seat stay just below the brakes. That one was useful right away when I was building up the bike.