It’s very tempting to modify Z-Wave configuration options via automations. An extreme example would be blinking the primary status LED on and off while a process is running. I’ve always feared this could wear out the device’s internal FLASH memory. I’ve got a bunch of NuTone dimmers from 2015 that continue to work just fine. Back then, I doubt anyone anticipated this use case. Modern systems typically cache/limit FLASH writes. Has anyone ever killed a Z-Wave device? I’m not talking about power supply (capacitor) issues, failed FW updates, or shorting the output.
That is a good question, not one I can answer based on direct knowledge. But is does apply to more than just z-wave, as I do something similar with Tado smart thermostats.
Tado offers external temperature sensors for around €80,= if memory serves me correctly. That is at least a 80% profit margin. Instead I have cheap external temperature sensors. If the temperature difference between the Tado thermostat and the external temperature sensor is too big, I automatically adjust the Tado temperature offset to match, effectively synchronizing the Tado temperature sensor with the external sensor. But that too will wear out flash I fear. I’ve been doing it with the main thermostat for two years now, the other TRV’s I just adapted recently. I do have some protection buit in to limit changes, but maybe I should limit it some more.
Luckily the external temperature sensors are more expensive than the TRV(!) so I can afford to ruin one TRV per room. 
If your zwave devices don’t contain cheaper flash than a esp8266 with a price tag around $2 then they should survive your endeavors with ease.
My esphome nodes are all set to save state changes to fash (so they restore the last state after a power cut) and all are happy and working.
Also the NAND flash typically found in modern SSDs have much less write/erase cycles (typically only a few thousand) then flash we find in esp’s for example (I think espressif stated a minimum of 100k cycles)
Wow, this is a question I never considered but now that it has been asked I’m genuinely interested in the potential answers! I have a few Z-Wave devices where I use automation to manipulate the device, a good example is my Honeywell thermostat backlight, I change the backlight level based on how bright the room is, so it changes at least twice a day and now I wonder “am I shortening the flash life of the thermostat as a result”.
I have a zwave doorbell that for the past 5+ years I have at minimum 2 device config writes to change the volume parameter every day. Sometimes it’s 4 or more writes. Even at 4 writes per day that is less than 10k writes to the flash memory in the past 5 years. and if it is the cheap flash that can barely do the typical 100k writes, I still have another 40+ years before it theoretically wears out.
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