Vault add-ins and their command sites are currently loaded on client startup.
My suggestion is that the command sites can be loaded or altered on user sign-in as this is currently not possible.
It would be very useful for removing or adding functionality that only users with certain privileges should have.
For example a normal user would in our Vault not be importing multiple documents, but they can still see the button and clicking on it would simply give them an error because they do not have the privilege to do so.
Instead what would be very useful is to simply not load that button, or remove it, if the user does not have permission.
The way I could imagine that working is through the .NET IExplorerExtension functions CommandSites, DetailTabs and HiddenCommands being called after the OnLogOn method.
Maybe something that can be switched on in the extension .vcet file:
<LoadAfterLogOn>True</LoadAfterLogOn>