You can connect several Serial LED register chains to the output multiplexer, which can be used for 7-segment displays at the same time.
In the example below pin #42 is used for the Output MUX and its pin #15 is used to control the register chain:
In the plugin configuration window, open the connected output multiplexer, then select the LED driver type (595 registers, DM13A Driver or LED Matrix) and click an empty multiplexer output (as #15 in the example above).
LED CONTROL OPTIONS
74HC595 Shift Registers DM13A LED Drivers MAX7219 LED Matrix MUX for LED Drivers LED Bar Graph Indicator Direct Connection LED Configuration