FWIW while I was in school in the US I got the cracked Motorola software(ran under WINE) in the early 2000s to, with a serial cable, SIM unlock and edit the IMEI among other functions on most period Moto phones.
I reset several phones to zero out the IMEI as an experiment (I wrote down the real IMEI in case) just to see if they would associate with network and they fully functioned for several years until I upgraded.
Those who live where the edit is illegal will read and not do, but those who legally are permitted will share an advantage that is for now reserved to those who have bought the unlock cable to process blocked stolen phones for illicit resale.