Let me put it another way then.. directly answering your question: Are they worth it? No, not with the complicated hole cutting and parts required to achieve the solution you came up with.
But if all you do is stick a button on each side of a control panel, then yes, I think they are worth it.

The second part of your answer is unrelated to the question posed. Notice that the question is about "Recessed" buttons, not buttons stuck on the side.
FWIW, if that hole is a complicated cut for someone, they're gonna have FAR more problems with the rest of their cab, and MAY not even GET to the part where they have to make a decision about cutting that "complicated" hole.
That hole is a simple jigsaw or router cut following an outline. 5 minutes at MOST, less than a minute in actuality, I'd guess.
The extra parts seem to be ... umm..... wood. Now, while you may not have -wood- lying around to do this, you most certainly will when building a cab. Kinda hard to build a cab WITHOUT wood.
Mebbe I just like it too much, but I don't even enjoy playing pinball and I think that's a cool feature.
My 2 pesos.