Sim Card from GrapheneOS to iOS

Hey,
i have graphene with a sim card. the sim card is anonymous so not activated on my name. My plan is to insert the sim card into an iphone 8 (ios 16.4) and run it as a hotspot, and hopefully it will solve my problems with the slow vpn connection.

My Question is: The mobile provider gets the IMEI on every connect to a cell tower correct? Even on graphene. But graphene does alot things to mitigate the attack surface (Frequently Asked Questions | GrapheneOS) much more than stock os and ios? How ios is compared to graphene? What there are doing worse? despite the imei which the provider always gets the access. What am i sacrificing if i insert his sim card from graphene to ios? Can the detect me and connect this devices together(very likely?)?

Maybe good to know. I use this sim card casually for normal phone calls and some doctors and my work place has the number. So just casually. I only activate airplane mode in the night. I bought this side by side with the graphene os pixel 6 for a complete new start.

I would appreciate any help.

Yes they can correlate the devices. Because your simcard has a unique IMSI. So all network operators you pass by know you switched to the other IMEI.

If you use the card where ever you go its likely not as anonymous as you think and easily tight to you. Especially if you use it in personal records.

I am not sure what your concern is exactly? What the switch will cause other than a link between the devices? What are you trying to defend.

Thanks for your answer. I don’t want to defend anything because i know i did mistakes. The Iphone would be the personal use phone and pixel for more private use. Since i gave this number to my employer i think it is already sacrificed. And i have problems with my always on vpn and mobile data so maybe the problem will solved on ios. and yeah sim cards are shit no matter if its anonymous (not activated on your name) or normal but i think it is important to select lesser evil choice. I will use the iphone as a mobile hotspot and but maybe sometime later a new sim card in the pixel so new refresh but it is already lost that the sim card provider has the imei of the phone.