Just wanted to add my +1 for this feature request. Yubikey authentication is one of the big things I miss when using Pulseway (it's oddly one of the few products that I use that doesn't have any Yubikey support at all).
I would like to request the ability to export your current list of notifications to a file for archiving purposes. This way you can clear all current notifications but retain the information for reference purposes.
Thanks for a great product!