Now having had a few experiences (https://www.claudiokuenzler.com/blog/1163/western-digital-green-ssd-dead-without-pre-fail-indication) with SSDs dying out of the blue, I think we need to add another sub-check to check_smart.
For Solid State Drives the TBW limit seems to be a good (?) indicator when the predicted "safe life time" has ended.

The big work is certainly to create something like a table with a general oversight of the TBW warranty limits of the different vendors and SSD models. Unless such a table exists already somewhere. Hints are welcome!