So, I think I'm figuring this out, even if it seems like a bit late in the game. Today I went through a portal to Raise and used their 4% extra on top of the typical kmart discount, plus a $5 credit that they offered me to buy a $25 gc for $17 - portal % - cc %. I have never gc2gc, so I wanted to start small. At the store I kept walking in circles looking for the gc. Finally someone asked to help me and they did. Went to pay with my egc/voucher, which was on my phone, and the card load failed. A manager override of some sort was needed, but thankfully it was the person who helped me find the gcs earlier, so we made a joke and he authorized override. Cashier refunded purchase onto physical kmart gc and we tried again. I had an eBay card just in case, but we tried Disney again. He thought the failure was due to it not being a physical gc. Maybe he was right bc with my refunded $ on the physical gc the gc2gc loaded properly. I wanted to try ebay, but didn't want to risk it for the ebucks 25 could have gotten me. Since I bought the Disney one, I was able to load it onto my account before leaving the register and confirmed the funds. Passed cashier the receipts and used Disney and kmart gcs (after snapping pics), and went on my way with my first gc2gc done

minor bumps, but success.
I bought gamestop too and will try that next week. Fingers crossed because it's much closer than Kmart! At least there's kmart. Thanks for the encouragement and info to try!
Do you all think an unloaded gc (say ebay or Disney) would work at another store, so long as they typically carry that gc but are out? Just curious ...
Congrats on your trip! I can't help but ask: did you rent points?