According to Shimano, the center of the hanger mount hole should be 4-10mm behind the center of the axle for road and 6-10mm behind the axle for MTB.

Have you considered offset mitering the stay and landing it higher on the hood? That gives you more surface area for your fillet and a larger contact area between the hood and the tube. In this case, it looks like you have already mitered the stay, so you'd have to shorten the rear end a few mm to make that happen.