If you request a mileageplus upgrade to business on connecting itineraries with a one of the segments listed as Polaris, you receive a refund if the Polaris segment doesn't clear by boarding even if the domestic leg clears: MileagePlus Upgrades | Eligibility & Upgrade Types | United Airlines

Does anyone have any DPs of cancelling the request after a domestic leg clears while the Polaris leg is still waitlisted and receiving a refund? Is the domestic upgrade clawed back?