Not sure what you are asking when asking about "quick die off age".
If you are talking about sudden death of hatchlings, in any species IMO it is a reflection of quality of husbandry moreso than a "normal" situation. Sometimes I suspect this could be just ignorance and lack of good sound knowledge of husbandry globally- such as in the case of many who have failed at keeping high percentages of jacksons babies from surviving.
I have bred and hatched melleri a few times. I found the offspring were quite large and sturdy and had very low mortality rates- maybe 0-3 per large clutch (memory is flaking out on me today, but seems like clutch size is normally quite a bit larger than 22). Honestly, I've found jacksons babies to be much more of a challenge than melleri.
Melleri babies are pretty easy to raise- keep them about like a big jacksons, but do not allow low temps to drop below 50, keep ambient temps below mid 70s (as low as mid 60s days were fine when I hatched them in the middle of the winter), and keep a nice warm basking zone ( Mid 80s or so- I don't use thermometer). that they can escape from as well as use when they want. Water 2x per day for about 20-30 minutes under a fine mist. Dust similar to a jacksons.
I raised my babies in 29 gallon reptariums laid on their sides. Each reptarium would have several babies, it would be packed full of twigs so all available space was available to the babies, a 60 watt incandescent light in a reflector was placed over one end of the cage, and a full spectrum flourescent tube was used in addition. A mist nozzle was placed inside the upper middle of each enclosure. This way, food and water and heat and cool are all easily available quickly to babies from anywhere in the cage.
The big thing to avoid is ambient heat about 80 or above, and dehydration. Melleri need lots of water. When ambient temps climb into the 80s, babies will heat stress if they cannot escape it. Oddly, if ambient temps are otherwise cool, they will often choose to bask right near the heat source and I'm sure their body temp climbs well above 80 quickly. But it is important they be able to move away from the heat as soon as they want. Perhaps they elevate their body temperature for only brief periods like this.