A want of waterproof glove/mitten covers not for mountaineering.

I don’t know any outdoor glove makers, but if I did I would ask them to make a short waterproof glove cover. Cyclists would use them, skiers, hikers, basically anyone but mountaineers could use them. And really how many times a year do most people need full gauntlet gloves?

Cyclists would love these for riding in the rain and to extend the temperature range of a midweight glove. You could keep them in a jersey pocket, or for hikers in a backpack. Anyhow Hind made a windproof glove years ago that was the right size.