I was able to obtain one of the tougher Walker cards in the 2022 Panini Mosiac line. This is a Sparkle Gold, which is a Super Short Print card. There are short print cards, then super short print cards, which are even scarcer.
Panini is always cagey about how many of these cards are actually produced, but you can bet it is not many. Notice they are NOT serial numbered. The blue, red and white sparkle editions of this card are already in the Hoard, but those three are not SSPs. The only other one that is, would be the green edition, which I currently seek. You will always pay up for these cards on the secondary market.