At the cost of some potentially reduced security, I've found that my iPhone will unlock while I'm wearing a full-face helmet as long as the chin bar isn't too high on my face, and the "unlock with a mask on" feature is enabled. It's hit or miss, but I usually give it a shot before pulling off a glove to passcode-unlock. It's worth trying again, if you haven't in a while.

> As a motorcyclist I can not even use FaceID with a full face helmet […]

This is why I like my Shoei Neotec (I) modular / flip-up helmet. Especially since I got it 40% off when then Neotec IIs were announced. :)

The integrated sun visor is also nice.