Just a quick update to all late fellas about to using Telstra smart modem 2 or 3 for other ISPs, this is their response
I just received confirmation from the Support Team that our Gen 2 and 3 modems are no longer accessible if the customer attempts to connect it to another provider and we appreciate your kind understanding to this matter. Cheers
Ver2: I am from the support team and there's no lock to the 4G back up that is locked. But when it comes to connectivity with other NBN providers that is not something we can guarantee. We only lock mobile phones not modem.
My gen 2 and gen 3 work perfectly with Superloop.
There was a firmware update a month or so ago and there was no reduction in operation.
Lots about it here
https://forums.whirlpool.net.au/thread/3z4yp6zn?p=145