Help needed: Software setup for 4-axis tangential stone cutter (Mesa)

Hi everyone,
I’m building a 4-axis CNC machine to cut marble and granite slabs. It uses a large vertical diamond disk, and the A-axis swivels the blade to follow the cut direction . I’m using a Mesa 7i92 for the control.
I’ve built several  plasma tables before, so I can completely handle the mechanical and electrical sides of this build. However, I have no idea about the software side of it. I’ve always just relied on the Pncconf wizard and have never manually edited HAL or INI files.
Could someone point me in the right direction for the software setup? Specifically:

1. How to configure LinuxCNC " A-axis that automatically follows the X/Y path"
2. How to set up the CAM software  so  the cut is perfectly to size without the top of the blade overcutting the part.
   
   Any  examples, component recommendations, or guides would be hugely appreciated. Thanks in advance!

Thank you for the response. I have an idea, but it is difficult for me to make it a reality.I thought that if the A-axis rotates very slowly, we could use it to cut the outside corners of almost any shape. My main problem, however, was cutting inside corners, for example, on an L-shaped countertop. For that reason, I wanted to use a bit to cut the inside corners and rounded parts.Let me try to explain my idea.The blade will be in the same plane as the Z-axis. The assembly will also have a bit mounted near the tip of the motor or spindle. The entire assembly will rotate so that the bit can become perpendicular to the slab, while the diamond disk becomes parallel to the slab.Both tools will be mounted on the same motor or spindle. The rotating assembly will not be considered another machining axis. Instead, I would treat it as a tool-changing mechanism:

• Tool 1: Diamond disk for straight cuts
• Tool 2: 45-degree diamond disk for bevels and angled cuts
• Tool 3: Milling bit for inside corners and rounded parts

Once I solve all of these mechanical and machining problems, my next goal is to make the machine very user-friendly.I will not be the person operating the machine every day. Workshop workers will use it, so the control system must be simple and intuitive. Ideally, the operator should be able to load a countertop design, select the material and tools, and start the job without needing advanced CAD/CAM knowledge.Thank you in advance for your help.

It seems a bit odd. I am reasonably sure that you cannot tilt the blade during the cut.
How much do those blades wander when you engage asymmetrical?
I have no idea, but I would be skeptical if outside contours are doable.
I saw that one in the Interweb.stylecnc.com/stone-carving-machine/4+1-automatic-stone-cnc-bridge-saw.html
For the price I would probably just buy it if not a hobby project.
The rpm problematic on said machine is obviously solved by using two separate spindles. (one vertical) one 90° tilted that can rotate around a pivot.
For square cutouts it cannot be all to complicated to figure out how to manually program the thing.
.... I think I need a wood panel saw with router.....
How capable is a water jet machine? 
How about a diamond coated steel rope? Seems there are options for that as well. The plate is vertical and the machines run around like one of those hot wire foam cutters. 
 

Master branch solves the A Axis alignment because I added some new motion.interp.* pins to it. One of them is motion.interp.heading which is the tangential heading or direction in real time. Look for motion interpreter Metadata Pins in this documentation link
linuxcnc.org/docs/devel/html/en/man/man9/motion.9.html 

I had envisaged there would be a companion component that dealt with knife alignment probably with external offsets with a setting that paused motion and lifted the knife if the next segment changed more than a certain angle (0 degrees in the case of the saw)

But I would look closely at FreeCAD CAM because one of their CAM developers Brad Collette (aka Siptronic) has done a bit of work with CAM for tangential cutters.There might be a ready made CAM solution.