Carpet python x royal python exists.
Carpet python x GTP exists
So by that math the GTPxRoyal is possible.
But my biggest question in these cases is....why?? I admit, I love working with the different genes combos. But crossing different species from entirely different parts of the world with different care? Definitely not something I would want to do. Maybe in an enclosed scientific study.... But as a general public and sale? Definitely not.
My other concern would be health issues. Sure, reptiles are a bit less likely to show signs of inbreeding/line feeding as quickly as a mammal, I don't know if enough study has gone into hybridization as well.
For example, ligers tend to be LARGE and prone to heart failure. Tygons tend to be almost dwarfed compared to the parents iirc.
Seeing people purposely breeding something for the 'cool factor's and disregarding possible health issues is just frustrating