Thanks to all who posted about earning points at Giant MD despite the ad not showing it, for the warnings about fraud, and data points on how these cards can be used.

Adding my data point:

• Purchased one Pathward (issuer) / Incomm (processor) Visa gift card for $500 + $5.95 fee at the customer service desk
• Go points didn't post immediately but were in my account within an hour
• Used card to pay Federal taxes through Pay1040, since I saw data points indicating the other tax processors were rejecting Vanilla Visa cards