A word of caution. Forks are the highest vibration and shock location on a bicycle. Objects that encounter the front tire or spokes often get lodged at the fork causing hard crashes, very often with head injuries and broken collarbones.

Make sure everything you mount on your fork is 'you trust your life to it' secure! (This includes handlebar bags and anything on the handlebars as well. My mom's flute playing is permanently slurred from injury to her mouth when she crashed from a loose strap catching her spokes.)

Edit: that said, I love LowRider racks and Ortleib panniers, both using the U-bolt adopters and braze-ons. So far, only my Mooney has ever had braze-ons and that only on the second fork he made me. (I crashed the first.) When I asked for the braze-ons initially, he said he wouldn't, that he was unwilling to drill fork blades. When I asked again for the second fork he said he would do it with English generator mounts if I likes but they would be bigger, more visible and take a larger bolt that would require drilling the rack hole bigger. I said yes and have never regretted it.

Ben