phospmph "awful hack" according to this previously mentioned post.
IMEI can be device specific like if there are 400k (the current estimated GOS numbers) devices that have one algorithm that produces the IMEI you can hide among them using that algo.
GOS argues that their are other identifiers, my argument make all of them rotatable, be it EID (which is flashed on the chip so maybe not possible but you can rotate by getting adapters), the user string can just be GOS, more research need to take place to make the GOS more anon and I think we can keep the security standards high even so.
People thought airplane mode couldn't isolate baseband and still broadcasts stuff to the carriers but GOS handles that beaughtifuly by not sending anything to the towers with airplane mode on.
Motorola may just be an assembler and get modem from some other OEM but I think GOS can get an OEM that does IMEI rotation beaughtifuly