I’ve created an API extension for triggering live radio presets on a given zone in Roon. Along with a patch for the Squeezebox Radio, this means you can use the hardware preset buttons when the SB Radio is connected to Roon instead of Logitech Media Server!
Details are in the README on GitHub, I’m guessing most people will need to use the manual installation method for the Squeezebox patch on the Radio, unfortunately, but I hope it’s of use to others. Seems to work fine for me so far, but YMMV…