InHand IR302 - custom firmware, TTL, Visible

[ghostrhetor]

looking for help and direction with router custom firmware, TTL adjustment, and Visible access...

with a Visible SIM in an InHand IR302 router/modem, ethernet to a Windows 10/Linux laptop, and two LTE antennas, internet worked decently for a good spell...
now they are limiting service because of an "unsupported device"...
would like to flash OpenWRT or other custom firmware to the IR302, but haven't found any that support it, and the InHand web interface doesn't seem to have appropriate adjustments (?)...

is there a way to use custom firmware with the InHand IR302?

what can be done with this setup to get around Visible restrictions?

thanks,
you