Making fixture for repeated cutting

I have a large part on which I need to cut just the edge. Actually it is going to be two pieces face to face to optimize cut path.

I want to make a sturdy fixture and not depend on holes in the cut bed. I would like to make the fixture pretty thick so threaded fasteners(that will hold the material, low profile screws like the ones that come with the WAZER) will not wear the metal out. Thinking of 1/4" (at least) aluminum plate and will probably go to stainless if it works out. If I make it even thicker, I can insert rivnuts with a counterbore underneath. There will be hundreds of little pieces that drop off after cutting since they are cut along the edge. Raising the material will also provide a good place for these pieces to go.

So the question is. Is it OK to cut a part that is far off the cut bed as long as it is well supported and the nozzle height can be set appropriately?