Running SetEVExchangePermissions script

Hi

Having run the above script, I don't have the luxury of being able to restart the Exchange Information Store as this is on a live Exchange server. How long would this normally take to complete? I'm not sure on what factors need to be considered - does it, for example, need to contact every DC or replicate data arrange EXchange. Could it typically take all night?

It's been about 2 hrs since I ran the script and deployment scanner is still saying the permissions aren't set.

thanks