Can I insert an NP-FW50 battery pack into the connection plate (for Z-series batteries) supplied with the NPA-MQZ1K, and use it instead of Z-series batteries?

You cannot insert an NP-FW50 into the connection plate (for Z-series batteries).

WARNING: There is a risk of hardware damage. If you forcibly insert W-series batteries, you may become unable to remove the connection plate, or the connection plate may be damaged.