spaceyjase I do indeed have that checked. I've also had it unchecked and tried the SharedArrayBuffer support on and off. I think what I'm trying to determine is if this is an itch.io thing (like a limitation of some sort), or a Godot problem, or both ― in order to figure out the best way to work around it.
At the end of the day I'd like to get this working for mobile browsers. It's uncomplicated (click to roll) and it's possible Godot is overkill for this, but my understanding is that this should work via Godot (and I'm hopeful it will).
Thanks for the tips! I'm sure I've missed something!