Just because two species are not genetically different enough to prevent them from successfully producing offspring does not make intentionally hybridizing them a good idea or indicate the presence of any benefit to doing so. Why risk the female being injured or dying, either by the male itself, being unable to lay the clutch, or from the stress and drain of producing a useless clutch of eggs, in the process of a stupid and pointless experiment?
There is no benefit to any way this would end up. At best, the two chameleons ignore each other completely and nothing bad happens (still nothing beneficial from the entire attempt). At worst, it kills the female, produces a clutch of weak babies that suffer before they die, or produces a clutch of hybrids that survive and encourages others to act irresponsibly and do it themselves. People should be working to breed pure species, not screwing with trying to produce crap.
Also, while 6.5" SVL is not as small as was originally described, as a general comment, responsible breeders should not use animals for breeding that would not have the opportunity to breed in the wild due to their size, health and condition. Responsible breeders should be selecting the largest, strongest, most active and healthiest animals for breeding, not polluting the gene pool with weaker genes or offspring from weak parents.
Chris