Cantilever -> V Brake cable routing

[Suprachrgd82]

Depending on the top tube diameter, Tektro makes clamp on cable stops

https://www.ebay.com/itm/305827491778

 

[Lhatch4]

I watched a couple videos on youtube of people drilling frames for internal cable routing to install dropper posts. I suppose the top tube of the Kona could be drilled for internal cable routing for a rear brake. It would be easier than brazing on a cable stop and having to repaint. It isn't a totally crazy idea. GT had internal cable routing for rear brakes on some frames in the early 90's.