Keep in mind that GTP and Carpet pythons are both of the Genus Morelia, and virtually share the same geographic range. Some subspecies of carpets are much more arboreal than keepers give the allowance for, so it's not a stretch to imagine "carpondros" in the wild.
If you do end up trying this, I would make sure the female is a ball python. GTP eggs are smaller than BP eggs, and you might run into even more problem with a slender gtp trying to pass larger eggs.
Just for the record, I'm not opposed to hybrids, but I wouldn't want to be the first time try a cross for fear of losing either of my snakes due to complications.