The Bambu printers do some cool stuff with measuring resonance to measure things like lubrication and belt tension. This is theoretically possible on any machine that can do Klipper’s inout shaping, but requires a LOT of data to be useful (from what I understand), which is orobably why we don’t see many printers on the market that can do that.

For thermals, Marlin (one of the popular printer firmwares) actually evaluates the control response of the heater based on the, rather than just looking at a specific temperature range. If the behavior is sufficiently different than what the system is tuned for, it will throw a temp error and shut down before thermal runaway occurs. I would expect other modern firmwares (e.g. Klipper) do this as well, but I don’t have as much experience tinkering with them and don’t want to make definitive statements.