It's safe now. The hole isn't any worse than a valve hole. Think of it another way. Manufacturers use the same extrusion for 16 hole rims and 36 hole rims. The only difference is the number of holes drilled in it.

There are a lot bigger things to worry about while bombing down a descent than a rim that has an extra hole.

Careful when you state with conviction things you don't really know are true!

There are bigger things to worry about bombing down a descent than a rim that has an extra hole, you say. Well of course, unless it fails, in which case it was the biggest thing to worry about.
I don't know if it's safe or not, neither does the OP and neither do you. That's enough reason not to use it.

What makes you think I don't know? I'm an engineer and a wheelbuilder, which doesn't necessarily mean I know what I'm talking about, but I have a little more cred than the average person.

I not only state it with conviction, I live it as well. I don't worry in the slightest about an extra hole in my rim. It is particularly innocuous in that location. It requires no more attention than your frame, stem, bars, spokes, seatpost, or any other parts on your bike, all of which can fail with little warning and cause a crash.



While bombing down a descent you are more likely to have a deer jump out in front of you, have a blow out, hit a rock, pop a spoke, wipe out on a patch of sand, collide with a driver who wanders into your lane, or have a dozen other parts on your bike mysteriously fail.

But if that extra little hole in your rim is really messing with your head, or you want an excuse to get something new, then by all means replace it.

I don't understand some of your logic.
Knowing there's a potential problem doesn't do much to protect you. Sure you could try and minimise stress on the wheel by riding exceptionally smoothly and avoiding any sort of road imperfections. You could try and minimise the consequences of a failure by riding slowly and and staying away from traffic. But seriously, what differnce is knowing there's a potential problem actually going to make?
You say "I wouldn't be bombing any descents just yet". When would you know it was safe to start bombing descents?

If it were My rim, i'd get a dremel tool to polish off the burrs, then I'd fill the hole with a structural adhesive- like scotch weld or devconweld