For sure. However I don’t suppose it is possible to do that retrospectively with the Librem 5 v1 ???
What you may be suggesting could be done in a number of ways e.g. directly putting a filtering chip between the SIM and the modem. or e.g. making the SIM virtual and putting the CPU between the real SIM and the modem. But presumably it is too late for trickery like that. ???
Limited to what could be achieved retrofitted … perhaps the firmware on the modem could be updated so that all binary SMSs (aka data SMSs / could alternatively be called application SMSs) are passed to the host for approval before doing anything with them. That unfortunately requires trust in the modem.
(Also in part being discussed in this topic Detecting so called "silent SMS" )
The article also contains the recommendation that there be
filtering at the network level to intercept and block “illegitimate binary SMS messages”
That requires trust in the government and the telco, and confidence in their competence. It isn’t a good long term solution.
The article comments
we have observed the S@T protocol being used by mobile operators in at least 30 countries whose cumulative population adds up to over a billion people
Does anyone have a list of those 30 countries? That would narrow it down to people who know for certain that they should be worried about this.