Comment by closewith
Yes, unfortunately in all modern calls there's a single Telematics Control Unit with a modem, GPS/GNSS, eCall (where required) and whatever OEM telemetry stack.
Like you say, there are always workarounds, but none that the home-gamer can safely or legally modify without taking eCall out of compliance.
There are standalone eCall units for retrofitting, e.g. [1] and likely soon more since 2G/3G gets phased out. Presumably you could disable the manufacturer’s built-in system and use standalone system instead?
[1] https://www.bosch-presse.de/pressportal/de/en/emergency-call...