Interesting, I think the design philosophy is that you know it's going to bend like a banana with the welding but everything adjusts on slots so you can compensate. It may weigh a ton but you have overpowered it to overcome that? :D

I think it will work well. Not sure you can pierce thick plate without angling in but you can always start from an edge or a pre-drilled hole.

I'm just doing the circuit boards for mine. I went for a solid iron bed with a lightweight aluminium gantry, but that's just me.

Problem is you really need a CNC plasma cutter to make the plates that hold the bed rails. I may just fudge the bed then cut them.

I think THC is fairly simple but hyped up as difficult so they can sell you the kit. If you buy kit you are stuck with whatever output they choose to give you and you rely on them to sort out your problems remotely. I like to feel in control even when I'm not :D

I want to get an oscilloscope on the torch volts and move it up and down a bit, see what there is to work with. I don't have an 'arc good' output so I need to detect the HV igniter sparks when the main arc fails.

The bit that still concerns me is setting to the pierce height on thin plate. I drop down on to the sheet until it takes the weight of the torch the back up. BUT, suppose it bent under the weight of the torch and then followed it up? You may think you are lifting when you actually aren't. I was thinking maybe fire a 40v spark down through the tip and see if it goes, but maybe that's over-egging the pudding.