Hope this isn't the wrong place to air this question. Let me know if so.
As I up the game to include Brass and Aluminum as materials to work with,  XY and Z ref take on a new slant. There I was trying to do a test piece in 13mm 6061 T651 plate and attempting to define the WCS as per the CAM workflow with my wood working probe gear. How newb can I get?
The new bed is conductive as will be the fixture plate that I am about to make, along with the mod vice and material. The gear I was using for non conductive materials goes into a drawer for now.
I have no experience  using the more in-depth probing sequence.
The market offers little selection as far as 3D Probes go. Prices jump from an idle to a full sprint.
I started with a~$100 item that states it has some anti roll feature.
It has a 6mm shank but we are installing it in a spindle with no brake.
As I am getting a handle on this device, it looks like that might present a problem.

Can someone explain best practice and which of the Mach4 probe methods to use.
thanks, chris

This is the device. It has a certain axial rotation that must be met and held firm to yield meaningful data, and failure can result in instant destruction of the internals. Also assumes the use of the highest grade of collet I have been assured. The instructions are not confusing as one might expect from the country of origin.
My concern is that there will be yet another step involved to secure the probe attitude during use.
As for Z Ref, I guess it is basically useless data even as an offset because of the nature of ER collets as are used.
SO I bought another tool setting device that is made interestingly enough by the people who brought us the WH-04 MPG.
Lots of neat possabilities no?

The bottom photo shows a low-cost version of the ubiquitous "Renishaw" touch trigger probe.  They have reasonable over-travel capability, 5mm or so I think?  They have to have this because apart from operator error etc the probing procedure can't stop instantaneously to there is bound to be some over-travel.  It isn't essential to lock the spindle as long as the probe point is properly centred using the adjuster screws.  Unless you are working to very close limits standard collets should be OK.  I believe you can apply a calibration routine that will measure and compensate for slight runout - I think a bit of code I downloaded as a Mach3 macro has that.

You're correct that the 3D probe isn't useful for Z setting unless you can set your cutters with a precise "stick out" which you store for each tool in the tool table.  I did have a go at that once by adding a back-stop to a collet chuck, but it was too fiddly and anyway rather suffered when I had a tool crash!  Easier to set the height for each tool when you fit it in the chuck.

I use the exact same tool probe that you have pictured, I actually am using it on 4 machines in the shop.
I set Work Offsets with it, X, Y, & Z! 

https://www.amazon.com/RATTMMOTOR-Automatic-Normally-Setting-Engraving/dp/B08LK93NTC/ref=sr_1_7?crid=22CVGMZGCWA98&keywords=tool+setter+cnc&qid=1689859527&sprefix=tool+setter+cnc%2Caps%2C98&sr=8-7

I use this to set my tool lengths. 

A lot of "Common Practice" is to have a know the stickout of the tool per the gauge line of the toolholder; however, I found it is much easier to just let your tool offset be the machine coordinate position of the tool setter position and let it be what it is.  All I do to get my Z Work Position is to touch off the work piece with whatever tool I want and add the work offset to that machine position, so if I'm using the Tool Probe in a macro, just add the Tool Probe's Length Offset to the current machine position at the point at which you want your Z Zero.
Then as a quick sanity check, the offset should be the distance between the tool setter and the work piece.  So if your material is 1.25" above the tool setter, your offset should be 1.25".
You have to have a known Machine 0 for all of this to work, so make sure you have a reliable way of homing your Z axis at least.
About as clear as mud I'm sure... but it works well for me on my Mach4 Machines as well as the '01 Hass I run almost daily. 
I then set up a tool length offset for the tool probe as well.