Hah! I actually made a thread on reddit about this earlier today. After thinking about it for a bit, I came to the conclusion that it may be nice to pair it with Solgaleo GX as its recovery partner as opposed to Lurantis GX. Also thought about it as a 1-of in a Xerneas Break deck that plays DCE. But here is what I said about the Solgaleo combo on reddit.
"The thought came across me to use it with Solgaleo GX. Naturally, the next thing to do would be to compare the use of this Rayquaza to one of Solgaleo's current partners in crime, Lurantis GX.
At first glance, the benefits are clear. It's a 1 prize basic that achieves the same purpose within the deck. Not needing to evolve is great as it saves space within the deck. Not to mention getting to play less vulnerable 60hp basics.
Lurantis does have the edge in survivability and in energy cost. Only needing 1 Energy to recover for Solgaleo. Although you can attach 1 to Rayquaza during Sol Burst and another during your recovery turn so I don't see the extra cost as being too relevant. Especially since you could now run all Metal Energy. And with that being said, maybe Magearna EX too to counter Sylveon GX."