No. The modem can also only be operated with the WAN connection (with the M4 Mini) or LAN connection with the Q7 / Q8 / R8 / Q9, i.e. completely without SIM cards. It is also possible to use WiFi with the Q7 / Q8 / R8 / Q9.
Another option is to use just one or two SIM cards. Which slot is chosen has no meaning. The advantage can be that a network operator is so bad in the area that the entire connection suffers. Then it is better to use a SIM card from one operator less.