Yep. That’s common. Not many of us use the estlcam firmware, we just export the gcode and then run it on the machine with the LCD or something. For the rambo, you should start with Marlin:
The way I do is that I make the shape in inkscape/a CAD-tool, make a cutting gcode in estlcam, then I copy the file to an old laptop running CNCjs that is hooked to the RAMBo. Voila! Super-neat workflow.