Plan-level permissions should have a way to sync with the global permissions

Currently (Planning v 1.x) when a Plan is created, it takes the global permission set as a temlate, and keeps it. 
When we do an update - adding a new user, removing users, changing who edits which Cost Object, etc - this has to be made in every open Plan. If we make a change that affects viewable data (including sensitive fields) this also needs to be applied to Finalised plans. While this isn't too onerous, it adds a risk we'll miss one, especially if we restore old plans from Archive.

What I'd like to see is on a single screen - maybe the Plans administration screen - an option to select multiple plans (tickboxes) and "Sync With Global Permissions", to update their plan-level permissions to match the new setup. 

As they'd be selected Plans, we'd retain the option to not sync them all, so preserving any use-cases where different plans are required to run on different permission sets. I wouldn't want to sync everything, then have to unsync some!


Alternatively, it might be useful instead to set a flag on any given Plan to use the Global permissions and not have it's own plan-level perms. That would achieve the same end, and I'm not sure which is better for your architecture. Either way, I'd like to minimise the time taken updating permissions for multiple plans, and reduce the risk that important updates aren't applied to all relevant plans.