Here is another way to look at this issue - I'm not offering advice just a suggestion:
Warren May is a fine craftsman. He builds beautiful furniture as well as dulcimers with care an skill. Warren is also a dulcimer player, and there are a few clips on YouTube of him playing out of D,A,A using thum and finger strumming style and fingerdancing with some DAA chording too. Warren also sings tunes and plays accompanyment. Now, if you have a maker who is also a player, and the instrument is a standard design of theirs (not a custom model where the customer has set the parameters), then it is worth studying the maker's playing style as it is likely to work really well on the instrument! Have a look at this video. You can skip the opening advert after 5 seconds, then go to 1.20 and there is a short section on Warren May's shop and you can see him playing and singing. Although the dulcimer he plays in the video has geared tuners and a 6+ - he is playing it in a style and tuning that would suit wood pegs and diatonic layout. And I expect he now adds a 6+ and geared tuners to many dulcimers because that's what most players want, but he still has wooden peg versions hanging on the wall behind him in the video.
If you look at the relaxed style of his playing you can see that he is really comfortable in front of the camera - he must have been playing like that for years to be so profficient. So you can bet that he built his dulcimers for many years around that style of playing - if not consciously then just by default.
Ok - I'm sure you can play a Warren May dulcimer in any style you want, and that's the beauty of the instrument. But wouldn't it be cool just to leave the dulcimer as it was made with wooden pegs and no 6+ and study the playing style of the maker on it?