IKEA Godmorgon Cabinet - How to combine and attach?

My wife would just like to have such extendable towel holders on the side. It would be a dream if there was something that combined both. Stable mounting for the countertop overhang and towel holder. But it will surely remain a dream.

Can you tell your wife that retractable towel holders are annoying. Who wants to keep operating that thing all the time? If she really wants it, you can find something like that at better kitchen supply/kitchen furnishing stores. But don't say later that nobody warned you that those retractable things are annoying.

What is extendable usually starts to wobble eventually. For kitchen towels v.lt. but even less there. The Ikea kitchen, for example, is hung on a rail. Surely you can use the same system for that as well. Cut the rail to fit, hang the cabinet, and that's it. Nothing will fall down as long as you don't overload it extremely. Kitchen wall cabinets hang on the wall (often just double drywall) and hold dozens of plates, etc. I generally prefer wobble-free, so always runners or, if possible, a support. But you can also buy some reinforced bracket or get one from the locksmith. The trick is to find the right fit.

We have Godmorgon with a solid wood board and shelf. We managed perfectly well with these brackets

We still had some small brackets left over from the IKEA kitchen assembly, which we screwed together with the board and the little cabinet. Although the board is really small, it has quite a weight... Let's see if our construction is still hanging when we come back to the construction site. We no longer attached the board to the wall itself.

whether our structure is still standing when we come back to the construction site.

What does the savvy craftsman say to this concern.....? "Where is this supposed to go?"