?

Good morning, I am looking for some advice and ideas for a project I am brainstorming. I have built a couple CNC machines in the past using Mach4/ESS, so I am comfortable doing it again. Now I am thinking about building a CNC welder for a production beam welding job that we do. I would like to control X,Y,&Z plus at least1 rotary axis for the positioner, possibly up to 4 rotary axis total. Overall travel would be approximately, 144”X, x 48”Y, x 60”Z.

My questions are;

1. Has anybody built something like this, that would have any experiences to share?
2. Is anyone using Mach4 to run a robotic welder? Good/bad?
3. If Mach4, is there a plugin or wizard or otherwise, that will allow me to build Gcode by jogging to points similar to programing a robot? Like a teach function?

I recently purchased a Vectis Cobot with UR arm, so I am familiar with robotics, but the reach of the UR arm is limited, not to mention the cost is too high for this job. I will keep using the Cobot for smaller intricate parts.