UPDATE

I received a reply from Red Wing:

> Thank you for reaching out to us at Red Wing Shoe. I wish I had better news for you. Unfortunately due to your gait, and how the leather has formed around your foot, there is not much else that can be done for these boots.

> You could try to find some very thin insoles for extra comfort but this may cause heel slippage which could be more uncomfortable.

😔

Lesson learned: don't wait too long with re-soling if you have a weird gait like me.