Thanks for the encouragement. I'll tell the kids about your compliments.
Anyone with kids knows it can be way more work to include them like this, but in this case definitely worth it.
My wife made all the other fixings, including this cajeta and key lime pie to finish off the evening. The cajeta (essentially sweetened goat milk reduced and caramelized) wrecked the color of the custard, but the complexity of flavor was amazing. Custard was nice and tart (I'm not that big on sweets).