Roof rust repair - roof rack “bubbling”

Curious if anyone has gone through the hassle of repairing rust around the roof rack mounting points. I use the roof rack on my Denali, and it still feels strong/stable overall. But it has pretty good amount of rust on the rear passenger rack mounting point. Not as bad on the driver side, but some there too, as well as some other scattered spots. I’ll be sad if the rails rip off one day with my skis or surfboard attached.

Tried searching, but didn’t really find anything on point. I figure it 1. requires significant body and paint work, 2. isn’t immune from happening again, 3. is super costly and the actual cost is somewhat dependent on location (I’m in San Diego). But this group has great info and is filled with gems, so I figured it was worth an ask. Feel free to point me to another thread if this has been discussed.

Any holes? Or just surface?

Might be good to remove the rack and treat it, assuming the bolts aren't rusted. If it lives on the coastline, that rust can start from the backside, although I wouldn't think that's the reason for the roof. Any other rusted areas?

Bugs and dirt can end up under the rack mounts, so maybe that trapped some moisture..

Usual fix is welding sheet metal patches and bodywork..