Just fyi some folk on bgg designed origami dice, mainly for playtesting games with weird die faces. Maybe it’s interesting to you to compare approaches.

https://boardgamegeek.com/thread/608070/origami-dice

Very cool - perfectly made for it’s use case.

I guess if someone gets to angry with the roll they might just eat the dice, but that’s a problem for another time lol

As you said, most of us probably have a fair number of dice, especially those of us who also do RPGs. Still, my main feedback is that would it still print well on A4?