Following @grahamrpugh's suggestion immediately provided a more than 230x reduction in execution time, the best we observed for a single "tuned" Extension Attribute script during this audit.
Background
Computer Extension Attributes — which allow a Mac Admin to collect extra inventory information — are one of my favorite features of Jamf Pro.
After having our internal opt-in Beta Testers report their experience with the new swiftDialog Inventory Update Progress script, we realized an Extension Attribute audit was overdue.