One thing I've always wondered is if you need a R15 sim card for it to use SUCI or if the old cards can receive provisioning to do it. I know for a fact you can use any USIM on t-mobile (so it had to support at least 3G) and it will work in the latest 5G devices without issue on SA.
You need a SIM card (ideally) with support for elliptic curve crypto, and some additional fields added in the profile (SIM services 124 and 125). You can then, once those services are enabled, place network public keys on the SIM itself.
There are 2 ways to do SUCI calculation - both require SIM support to hold public keys. SUCI-on-SIM requires a SIM that can do the encryption to the public key on the SIM itself, and issue that in response to the IDENTITY command; SUCI-on-phone requires a SIM that "just" has the public key fields present, and the handset can do the SUCI calculation and encrypt the SUPI for the public key stored on the SIM.
Either way, your scenario isn't using SUCI concealment by my understanding, unless you got a new SIM card, or it was reprogrammed somehow to support the SIM service fields needed (but I'm not aware of operators doing that).
