to get chromatic or not
Instruments- discuss specific features, luthiers, instrument problems & questions
A lot of this discussion addresses the challenges facing people used to a diatonic fretboard who switch to chromatic and need visual cues (position dots, gold frets, etc.) to help them adjust. In other words, the answer to the question is YES, you can play diatonic music on a chromatic fretboard, but you may have to overcome a hurdle in learning the layout of the fretboard.
In my mind there are two distinct reasons to play a chromatic instrument. One is to play modern music like jazz and some pop/rock for which the dulcimer was not originally intended. A good example of that is @sam-edelston. I don' think you could play Queen's "Bohemian Rhapsody" on a diatonic, but Sam pulls it off swimmingly on a chromatic! Another reason is to play in different keys, and a good example is @erin-mae. She basically plays diatonic music, but because she often plays in multi-instrument jams where the keys change rapidly, she uses a chromatic. No need to re-tune. No need for a capo. Have dulcimer, will travel.
For any individual out there attracted to a chromatic dulcimer, I say "go for it!" In the long run, your understanding of music--even diatonic music--will be enhanced by the fact that you can visualize an entire chromatic fretboard and see the diatonic patterns therein.
But as a community, I think dulcimer players should still embrace the diatonic fretboard both as the historical origins of the instrument and also because of the simple learning curve. Beginning players can learn the dulcimer quickly because of the relative simplicity of the fretboard. That doesn't mean the instrument is limited to simple music, but merely that this humble instrument is more approachable than, say, the violin, which takes a year or two of serious practice merely to play badly. The accessibility of the dulcimer is one of its most attractive attributes. It is a big part of what makes the instrument so special.