You can use MUDI router to connect your phone to the internet using vpn or tor. every month/week you can change the data simcard whenever you want but before you change it, you need to reset the imei using BLUE MERLE then you can insert the new simcard.
Here i use
disposable DATASIMCARD(inserted on mudi) + VPN (OVPN) + GRAPHENEOS (PIXEL 6a)
make calls for some clear-line i use (mobilevoip)/VoIp Raider
receive calls only through simplexchat or signal (fork)
on my laptop i use qubesos connected on ethernet port on mudi + sys-whonix + internet
thats it.
ps: blue merle only works on firmware version 3.215 but i have recently sent an email to nicholas farnham and hey plan to release further updates in the coming months so this may change, anyone can see the updates on theyr github repo once they have been finalized.