In the future, when making these requests, please give a description of the snap, the url in the store and why the auto-connection is needed.
Hiri is: https://www.hiri.com/
I guess it is plausible an email client would want to access USB keys, but it shouldn’t really need it be default? Ie, shouldn’t this really be up to the user? (Perhaps until gnome-software has a way to do this, we should auto-connect for now).
As for mount-observe, I suspect this is just a noisy denial and not actually required. Does the snap operate ok without it?