couple of things from my build. if you use the D series instead of the PWN series drivers you can get the dimming curve starting at 5% instead of 10%, although visually you can't tell the difference. If you are looking for true sunrise/sunset i'm afraid you'll be dissapointed. the ELN series, specifically the 60-48 is built this way and you can't get around this unless you could hotwire some kind of microcontroller for a super-duper slow duty cycle.
As for thunderstorms/lighting etc. as far as I know, very few controllers can do this and probably none can do it with DIY. Lightning is a neat gimmick but don't get hung up over it, it's not that big a deal.
Any limitations here are definitely a driver limitation. Perhaps you might look at the buckpucks? I thought i saw that they have a new one that can handle more than 6 LED's. Or look into the homebuilt ones, I know DWMZ has a monster thread on here discussing it.
Also, check the prof forum. I think someone had a way to wire more than 3 meanwells per channel safely.
Second, this driver has a built-in safety measure for capacitance discharge (don't ask me the details, i don't understand it all) so the lights will flash when hitting 0%.
