Yeah, you're right, you won't gain anything coz you already paid for it but then you would have to loose it, right?
You can only do hot swap it you installed the Pin Header. Boot with the good X2L, once booted, unplug the good one and insert the bad one, hopefully without hurting yourself in the process and without pulling the gray and black wires. Flash using Evox dash. Go to Xecuter forum and there's a tutorial there. Note, you don't need to worry about the gray wire, you don't need to attached the gray wire of the bad X2L, just plug it in the Pin Header. You can try attaching the black wire if flashing fails. Be careful coz you'll be dealing with an open box and live wires. Don't let your sweat fall on the MB.