Regards using a noter. I agree they are quaint and uncomfortable and would not be my first choice. However Jean Ritchie's dulcimer book, "The Dulcimer Book", Oak Publications 1963 discusses the Noter and explains technique. Google Using a noter and there are several videos that will show how they are navigated.

Lap dulcimer fret spaces correspond to the fret spacing on any guitar. The exception being the frets needed to make a dulcimer fully chromatic are not used or removed entirely. Think piano in the key of "C". no black Keys.

I have long thought a Tenor Guitar, even a six string, set up like a dulcimer only held as a guitar but played like a Dulcimer would be a good possibility for a person with some limitations. You would have to learn the possible tunings and what frets to avoid but that is a matter of using a good tuner and the simple marking of the frets.

Martin Guitars made just such a device I believe.

Don