Nighthawk M6 and Nighthawk M6 Pro qustions

Hi,

I am enquring about the following:

Nighthawk M6 Pro 5G mmWave WiFi 6E Mobile Hotspot Router, Unlocked, up to 8Gbps

Nighthawk M6 Pro Mobile Router device and battery (MR6550)

1. Unlocking the device.

If I buy either of these from Telstra. Can they be unlcocked after the payment plan.
So I can transfer to another provider.

2. Pre-Paid Sims.

Can they take prepaid sims?

Thanks

Ward