Re: SD Cards?
Most top-of-rack/access-layer switches and branch routers don't have easily removable SD cards. It's more of a common thing on enterprise-grade routers, core switches and carrier-grade equipment, but usually these cards fail once in a blue moon (usually as a result of a power cut or PSU failure). Most of them only use the flash to store the firmware, once it's loaded everything runs in memory with configuration saved to seperate NVRAM. They shouldn't be making excessive write cycles to the flash storage, regardless of format.
I can count on the fingers of both hands the number of flash cards I've had to replace in 10+ years as a network engineer. If I was having to replace cards every four months across a line of switches, I'd try my very best to make sure that vendor never gets picked again at the next hardware refresh.
Biting the hand that feeds IT
