When developing WATTS macros in a Global Site Variation, previewing* can be used prior to setting it to test traffic.
Global Site Variations have an advanced option to set "Apply Based on Campaign Assignment" to "Preview traffic only".
This enables testing a Global Site Variation while previewing a campaign.
When previewing in SiteSpect from the control panel, SiteSpect creates temporary unsaved preview session and as a result, the IDs shown for WATTS macros for Campaign ID and Variation Group ID pairs are temporary and not accurate (e.g. -999 for Campaign ID and a random ID for Variation Group ID).