A company has been rocking the frankenbike from their factory for a while! It's called the Lauf Seigla - 2.25 tire clearance with 700c rims, suspension fork (not a MTB suspension), XC MTB geometry (mostly), drop bars (a very compliant one at that), UDH, 1x only, 17-18lbs!!! They also sell the entry level version, which has electronic XPLR, for $3500 (ish). Bought one, it's fast. I think you could objectively say it covers the MTB end of the gravel spectrum quite well but I'd love to see more data on the other end of the spectrum - aero gains or losses.