Vault should recognize activity in open files or alert if about to Timeout.
I often work in Excel or Word files for extended periods of time which I've opened from Personal Vault, but it doesn't recognize that activity and locks the Vault after 20 minutes. I've lost significant work since the Save function is suspended after that, requiring me to download the file locally, then re-uploading and replacing the original file, then going back and deleting the local copy. Big hassle and compromises security since the once secure file now resides in an unsecured local directory.
An alternative but better than it is now, would be to provide an alert or popup in the open file tabs when the time is about to expire, so the user can instruct the Vault that work is still underway. There is currently a popup alert in the Vault directory, but if I'm working on a file in another tab, I can't see it.
A third alternative would be to allow the user to set our own timeout limit.