Have a look in the Vagabond thread, there’s a pic of a CX chainset with fag paper clearances to the chainstay. So yes it fits, but depends on what size chainring you want to run, and how wide a BB you fit (for sq taper).
I’d go MTB, or an older set of CX cranks and square taper BB.
Do you need a 50t? That’s as high as road bike and it’s;
a) got slower tyres, less aero, weighs more, etc
b) bigger tyres/wheels = higher gearing, a 46t would be the same as a road bike with a 50t.
c) road bikes often don’t have an 11t anyway, so you’re already gearing over and above that with an MTB cassette.
I was looking a them and thinking along the lines of a 28-42 double which you can get from shimano’s MTB offerings.