MQX wouldn't prevent you from using the switch, but there just wouldn't be code to enable and make use of the switch feature. MQX puts the switch in bypass mode.
IN the RM 46.1.2, "Can be configured to operate as a 3-port switch (switch mode) " and is it possible to use the switch working at this mode in MQX or without OS?
MQX wouldn't prevent you from using the switch, but there just wouldn't be code to enable and make use of the switch feature. MQX puts the switch in bypass mode.