I recently realized that it looks a bit goofy to run around with the open umbrella all the time (especially in third person). I tend to keep it in my off hand because of the mobility it offers, especially with the charm of the raven.
I thought it might be a nice feature if the character closes the umbrella and carries it in the off hand until it's either raining or they need to glide. Maybe even as a toggle for people who like the open umbrella at all times.
If you press H to hide your hands and then 3 for example to select the knife in my case of your tool bar to be able to us it you now have the umbrella hidden, if you change to any 2 hand weapon and swithc back to 1 hand the umbrella appears again