I have same router,
the new firmware has support Quectel EM12G cat12 modem
my current tower do not support CA mode, I will find another place to test.
you can download from https://www.dropbox.com/sh/wv6c78uuimtrbtq/AADcAO8LgmnhGRzh7qdAHBVpa?dl=0
all about quectel EM12G (spec doc, latest firmware ,upgrade tool, linux driver guide etc) :https://www.dropbox.com/sh/wv6c78uuimtrbtq/AADcAO8LgmnhGRzh7qdAHBVpa?dl=0