Trek fx3 fork to post mount?

I have a pile of parts that I’m trying to cobble together.

Among them is a trek fx fork. The calipers i have available are post mount. The adaptor I found won’t fit, due to the fender mount visible in the image, immediately below the caliper (image from Internet). It seems to me that all adaptors to make a flat mount accept a post caliper require swooping down, and will therefore interfere with this fender mount. Am i correct? Is there a way to make this work? I’m tempted to just dremel off the fender mount, but I’m not 100% sure that it’s just aluminum at that point in the fork. If it is, would cutting it off be an issue (besides no fender, which I’m fine with).

by nodarkhistory