I'm doing quite a bit of an educated guesses here from my limited experience with the DM430, but they seem to use STM32F777 series and their flash cycle per datasheet is about 10k cycles if my memory serves right, however they could be using an external NVRAM for data storage which would make it a bit impossible to guess unless just opening one of those displayes and look at the hardware inside. What I believe plus1 is doing is writing stored values to EEPROM which has ~100k write cycles (or at least that's how I'd do it).
The better question is, why would you need to write so often to a flash memory or eeprom that this is a question, unless for pure education purposes. (I also assumes plus1 is doing something in the background to preserve flash or eeprom memory, or at least they should).