> The plan is to equip them with some sms gateway software and ship them to some customers.
just a warning: if you're in the US, this runs afoul of 10DLC regulations the carriers self-police. carriers can and will smack your peepee if you try to use random phones for SMS marketing.
https://www.10dlc.org/en/verizon-tmobile-att-sprint-carrier-...
i do see you're using this overseas and encountered similar issues[1] running commercial GSM gateways, but just a heads up for anyone wanting to do similar in the US (even with programmatic systems like twilio).
[1] https://ciboulette.net/blog/2026-09-05-desactivation-de-l'en...