Hi @Mark-Lee ,
Chad is correct in that we have not tried it, but my idea is that if you wanted to access the Linux shell on the modem card, you would need a modem development platform from Quectel.
Here is an example I found online (please do your research to ensure this will work for you, but I do see they mention serial port access):
https://www.aliexpress.us/item/3256803611119964.html?gatewayAdapt=glo2usa4itemAdapt&_randl_shipto=US

In our architectures, we do have a mechanism to talk to the serial port over software using one of the QUPs, but there has been no need to do so, and would be a costly SW expense to develop it.
If you are willing to void your warranty (not recommended), I can show you which resistors have it and you could try to solder on to them, but you are better off with the Dev Kit IMHO.