I just got a new (to me) bike, and while it's great in most regards, it has no provision for mounting a rack. Rather, it does have eyelets on the dropouts, but the fork crown isn't drilled. There is a divot in the back to help start the hole, but I was wondering about taking a different approach.

I've seen a few bikes use a system like this

to mount a front rack, and it seems like a great way to go. Does anyone have any information about doing this to an existing fork?

It is an ingenious approach since there's usually much more meat on the crown than on blades. There might be one problem if you try to do it on a finished fork with a square top like this one. There might not be enough clearance between where you want to drill and tap and the steering column for most power drills, so you might have to get creative.

On a sloping crown be sure to fixture the fork so you're drilling close to square with the top, otherwise you'll have problems starting the drill without it walking.

A recent issue of Bicycle Quarterly reviewed a bike with a front rack mounted in that fashion. It appears that a loaded rack flexes and thereby transfers a turning action to the mounting bolts, causing them to loosen repeatedly.

same framebuilder that Custom builds the rack would braze in a threaded boss into your fork crown, then you get both painted or powdercoated.

there are long discussions on how the handling is better with such a front load by having a fork with more offset, and so less trail ... thats the way the original Parisian newspaper bundle haulers had their bikes designed. BQ rhapsodizes on that stuff

Then again, off the shelf. There are Racks that would mount using the same bolts that hold the V or cantilever brakes on. Old Man Mountain offers a few

and there is a Tubus Smarti , seems in European distribution , if you are over there , EZ, Retailer shipped across the pond if not . pannier racks.

and there is Paul's Flatbed rack , an aluminum/Wood slat rack somewhat of the type you pictured,
But uses 1/2" aluminum rod stock
for the support rail around the cargo area and the support struts, into a CNC socket fitting in the edges..

And there is a bracket that fits around the steerer tube above the headset or the stem Quill .

Quite adjustable , no welding involved.

https://www.paulcomp.com/flatbed.html

If it were my bike, I'd use (or complete) the hole in the fork crown normally intended for a caliper brake and mount the rack using a bracket from that hole. If you ever want to mount fenders, you will need the same hole so might as well have it.

Even on a steel brazed and lugged flat or sloping crown fork, I'd be leery of drilling and tapping into the crown at those points. It sure does beat drilling into the legs but still.....

So no one has any actual experience with this technique?

I sent the person who built the bike pictured above a message, and if they get back to me, I'll post it here for future searchers.