Manufacturer issues remote kill command to disable smart vacuum after engineer blocks it from collecting data — user revives it with custom hardware and Python scripts to run offline

I'm no law expert, but as far as i know, there were already similiar cases. Reasoning (german law): Software required to run the product is not "licensed to use" but part of the product, which was bought, belongs the user and not the company. Remotely making the device unusable would indeed violate that term.

Hopefully, such terms would violate the above law and not hold up against it.

At least in EU the manufacturer can't revoke licenses on sold physical products with no cause (can't expire before EOL either) and can't remove advertised functionality. If any feature is conditional or temporary it has to be disclosed before sale.