To have a "wing" at all whilst hypersonic begs the question. Do we need a wing at all ?? Save for down low, and transition back from Bullet to Truck ??
variable geometry or retracting geometry??
The Valkyrie had a nifty feature that drooped her outer wing, moving a wing 90 degrees loses all drag due Lift, and we are left with parasite, retaining all cargo and systems volume.
bear