I can still imagine that after the update, one could simply run their own update again, if everything necessary is available.
But the easiest thing is probably to make a really big detour around every authorized repair shop.
Well... it's a questionable thing...
Firmware updates are usually installed to achieve an improvement.
This can affect all aspects of the engine's operation. Some updates are certainly beneficial, so in those cases, you should only change the calibration tables and avoid downgrading the rest of the firmware.
'By the way, I haven't seen any TSOP sockets yet... but with the right soldering tools, these parts aren't a problem. However, I wouldn't let just anyone work on such an IC unless they've already demonstrated that they can solder.'
CU Gremlin.