Figure I would post on here as all of a sudden I seem have been bombarded by people with a sudden interest in Cyrtodactylus.
First of all I don't consider myself by any stretch of the imagination as anyone who really knows a lot about Cyrtodactylus. Yeah I keep/breed a number of species (7 or 8 I believe, haven't counted) and have had some success with them (around 45 babies of various Cyrto. species last year, from various species). However this genus is so huge that I only know what the top of the iceberg looks like. They are describing new Cyrtodactylus every year and they probably will continue this for atleast a few more decades as Southeast asia itself is a hotspot for new species.
Anyways, I don't believe anybody in the world has produced enough Cyrtodactylus ( let alone a single species like peguensis) to have any real data/numbers to suggest that they are TSD. You really need a large number of offspring all kept at varying degrees of stable temperature in order to determine this. Cyrtodactylus in captivity, as Leland said are in the stone age in terms of what has been accomplished with Leopard Geckos, Ball pythons, etc. These are species that have been bred in captivity for decades, Cyrtodactylus on the other hand are now only kept by a small handful of people and are still a gecko that not a lot of people even know about--other than maybe the cheap pulchellus or intermedius you see half dead on importers list from time to time.
Also from my experience, Cyrtodactylus eggs seem to be do better when provided a range or temperatures, instead of being left at a constant temperature for the duration of the incubation period, so this being the case provides just another challenge in trying to figure out TSD.
I think you are doing good right now if you are just able to consistently get babies from these geckos and maintain a viable population of them in captivity. Its not an easy thing to do, especially since each species is rather specific in the niche it is designed to fill in the wild. Also supply of animals is another factor, not a lot of people care about them enough to want to invest money to import them. Its also tough to convince yourself that producing a lot of these geckos is a good theing when no one wants to buy them for anywhere near the price they should really cost. It wasn't until someone on here posted a video of a peguensis chirping that people seemed to think they were "cute" enough to work with. News Flash--- pretty much all Cyrtodactylus are capable of making an audible sound (as are the majority of other geckos), so the basis of wanting to work with a species I think should run a little deeper than the sound it is capable of making--seems rather shallow to me atleast.
I think Cyrtodactylus is an incredible genus of geckos with so many unique species and characteristics and they are very impressive when kept properly.
Derek