In the world of the Russian Garmon there are a couple of tunings/timbres that involve two sets of piccolo reeds. These include combinations like LHH, LMHH, MMHH which are absent in the Western tradition. I dont know if there are some underground diatonic scenes where players/builders experiment with such tunings, but at least in the PA and CBA worlds this doesnt exist (as far as I know).
Here is a (Google Translated) page with a few snippets of such tunings:
https://translate.google.com/transl...armoni-i-ih-zvuchanie.html&edit-text=&act=url
And here is a longer clip of an MMHH garmon (which also includes a high reed in the bass):
Here is a (Google Translated) page with a few snippets of such tunings:
https://translate.google.com/transl...armoni-i-ih-zvuchanie.html&edit-text=&act=url
And here is a longer clip of an MMHH garmon (which also includes a high reed in the bass):
