No problem at all with drilling the fork crown. It's done all the time.
The normal caveats that your brother surely understands apply, especially to ensure that the exit hole is on axis.
Drill it at center height so there's ample material above and below, but that will mean that you'll need shaped spacers front and back to meet the curve of the crown, and probably trimmed to clear the crown race.
Lastly, finish by painting, or using grease on the sides of the hole to prevent rust.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.