For some reason people on HN think if something isn't useful for their specific workflow, then nobody should have it or use it.
On the keyboards that support it I've had it remap to another layer if I hold it, but I'm thinking of using it for escape/ctrl, as I do use some emacs commands from time to time (mostly evil mode, but not everything). But I haven't decided where to put my layer switch key yet.
Edit: I won't hold out that long here. Here's the link to the feature to make this possible for anyone interested: https://docs.qmk.fm/#/feature_advanced_keycodes?id=mod-tap
It's spelled "Raymond Luxury Yacht", but it's pronounced "Throat-wobbler Man-grove!"
"You're a very silly person and I'm not going to interview you."
This keyboard is using this $27 set: https://www.aliexpress.com/item/33006008300.html