AIP Unified Labeling client policy update frequency?

We're piloting sensitivity labels to a group of 12 staff who have had the AIP UL client installed on their Windows 10 laptops.

While in pilot, we change the published labels that are in the one policy we are publishing.

Thing is, the staff have varying experience of when the labels appear in Outlook. Is there are way of forcing the UL client to update or otherwise control the frequency of 'calling home'? Looking at the guide but don't see an GPOs to set for this.