It might be worth noting that I was running Azahar through Vulkan... which ... I think is currently listed as an 'experimental' level of support by Azahar's website.

It recommends OpenGL for better support and stability.

I ran around more in Kokiri Village, no more audio spikes. I think its just due to how certain cutscenes quick load scene transitions.

Also, I completely didn't expect this to just work, but it does:

The secondary screen, that's touch sensitive on a 3ds?

Well the Deck's screen is touch sensitive as well.

Worked just fine to navigate through the map and item menus and what not, just poking the Deck's screen itself.