Having been through a similar situation, there is no easy solution. The problem with moving the lower cage bolt up is that the plates don't line up, as 2nd photo shows. The problem with using a MTB triple is the small difference in ring sizes. You would have to gap the inner plate to the middle ring, which would leave a large gap to the outer. That could work but the chain will overshift the big ring rather easily. Gevenalle makes a CX FD for slightly smaller rings but I don't know if it can handle a triple.
https://www.gevenalle.com/product/bu...nt-derailleur/
You might try to find a MTB triple FD with a large inner plate and then shave it down for better clearance.