Just looking at my next 'last bike ever' which has boost wheel size spacing.
According to Hope the boost hub is a different size.
According to DT Swiss you just change end caps on a 'standard' hub.
Do spokes need to be adjusted for the DT solution and which one is better?
I have DT rims on 240s hubs.

A hope boost hub has wider spaced flanges so the freewheel sticks out more giving more tyre clearance to the chain. You (may) need to space out your chainring to match. If the DT swiss end caps keep the hub centralised then you won't change the chainline so you defo won't need to space out your chairing

You can boost it a little bit (3mm) on each side, 3mm on the rotor and adjust the mech to fit, or do all 6mm on the disc side, space the rotor by 6mm and dish the wheel.
You should be able to get either type of spacer for a 240. MRP do some and there were some on sitw that were nice and cheap.
Is it centrelock or 6 bolt? I haven't seen as many centrelock boosters, but I think they do exist.

Thinking out loud.
Had not thought about the disc side but it starts to make sense when you do.
The chainline is already set up and I would not want to fiddle with the cranks that so it would require the cassette to be positioned to match.
This means the disc requires a spacer. Calipers have some float adjustment so that should work.
Its more likely though that the adjustment is not symmetrical so the wheel is not sitting on the centre line of the bike?
This all feels like a bit of a bodge. If you are going boost then go boost properly or not at all.
In fact scrap the new bike idea and get that Ramirez guitar you have been looking at.

Mariner wrote:...and get that Ramirez guitar you have been looking at.

Tasty! :) Hefty pricetag though.

Greetz

S.