Many common NOR flash and EEPROM devices are rated for ~100k program/erase cycles. If the firmware is simply rewriting the same block on every parameter change, 100 writes per day would hit the limit in about 3 years.
However, if the logic was designed to spread the wear out across multiple blocks, it could potentially handle millions+ of updates.
If it’s NAND flash, it probably already uses leveling due to the need to work around bad blocks.
(Side note: my Pioneer car stereo puts a read/write ext4 filesystem on raw SPI NOR flash. It writes to this filesystem whenever you change the radio channel or play a new track over Bluetooth. This is an extremely bad and not-recommended design, but so far it’s lasted 7 years and counting. Quite possibly it will outlive the vehicle itself. So YMMV)
Heat is a contributing factor; it’s possible that relay based switches would last longer than triac based.