Ian, in a general sense most software provided by machine makers are just gcode senders and not CAD or CAM software. A gcode sender’s main function is to send the text files containing the gcode which commands the firmware on the machine to do what it does. ie move the tool around and control tool. So there are lots of GCode senders out there. LightBurn started as a GCode sender for 2D laser cutting with added features for setup and positioning of the design. It’s come a long way from that and now has lots more design capabilities too.
Once you have a GCode sender to get the GCode(also called toolpaths) to your machine, you need software to create the GCode/toolpaths. CAM software does that and many creation tools(CAD) have plugins for toolpath generation. You might look at Kiri:Moto for CAM and for GCode senders, there are many. Opensource options like CNCjs, OctoPrint, and many 3D printer GCode senders would work. Some will run on $40 Raspberry Pi mini-computers so you don’t need to have your main computer connected to the machine.