Why the 1:18 ratio on what were otherwise similar data sets?
The one with 90,000 proxy objects in Meeting Maker wanted to give everybody in Outlook Delegate access to each resource. In round figures 100 resources times 900 people gives you 90,000 Delegates.
So we were looking at using our usual method for setting Delegates (which would take a long time).
But it's actually simpler than that.
Meeting Maker does not have a default level for giving EVERYONE access to a resource.
BUT Outlook DOES!
And PFDAVAdmin makes it easy to propagate these permissions centrally (so long as you have an Exchange Admin who's willing). In this case it's criminal not to use it.
You can set up an import file as we've documented before, using
to provide read-only access.
Or (quoting liberally from the documentation for PFDAVAdmin),
The Set Calendar Permissions option enables you to perform a bulk edit specifically to change permissions of the Calendar folder so that a single operation can modify the settings of thousands of users on a server. This is useful for changing the default permissions setting of the Calendar folder of all or many users, so that team members can view other member's calendars. Using Microsoft Office Outlook® enables changing only one user at a time, so the Set Calendar Permissions option is a good solution for this kind of task. In addition to changing the permissions of the Calendar folder, by using this option, a bulk-change also occurs on the permissions of the FreeBusy Data folder (hidden folder) of all the users on a server. If the FreeBusy Data folder permissions were not changed, the users will not be able to access another user's calendar.
I was going to start taking screen shots of how to do this exactly, when I said to myself, "Self, someone must have already done this."
And so they had. Thank Amit Tank whose FAQ: Give Calendar Read Permission on all Mailboxes - PFDavAdmin admirably takes you through this.
For international users, Set calendar permissions with PFDAVADMIN goes over how to filter for translated "Calendar" folders.