I AM EITHER BONKERS OR NOT. what do you think?

I think the former.

Hmm. My first thought was "definitely not." My second thought was... maybe. Looking at recipes for mochi waffles, the batter texture ends up similar to a popover texture. It's just about whether the non-gluten-containing glutinous rice flour would withstand the puffing. I would try an established popover recipe (such as this one https://www.seriouseats.com/the-best-yorkshire-pudding-popover-recipe) to get the egg ratio right but with the mochi mix as the dry ingredients. Adjust liquid to get the correct consistency. And please report back!