Greetings,
A modem firmware upgrade is typically performed only when it is mandatory specifically, when we know that updating the firmware will resolve a confirmed issue.
In most cases firmware upgrades are carried out only after the underlying problem has been identified. The commands required for this process are not publicly available, as incorrect use could damage the device.
If you believe a firmware upgrade is required for certain features, please let us know which features you are referring to.
Best Regards,
Justinas