Toolchanger: Coordinate systems, Z-Probe Offset XY

[Chuckonelli]

Hello Guys

I'm currently trying to understand the different possibilities to set up the machine coordinates for my toolchanger-System (hackaday.io/project/175489-changer-a-toolchanger-new-interpreted).

My main coordinate system G53 is in the center of the bed / middle of the kinematic coupling.
I want to have the toolhead X-Carriage (if no offset is active) exactly in the center of the bed. Therefore I've set the exact X-Endstop and Y-Endstop value in:

M208 X-181.1:181.1 Y-154:139.65 Z0:280 C0:240 S0 ; Set axis maxima & minima, 0 in Center of Bed

So far so good. But the actual Z-Enstop switch on the toolhead has an offset of my desired center of the toolhead (x-carriage) therefore if you would probe without any active offset you would be off-center.

The offset of my z-probe is in x-direction = 0.1mm:

In y-direction = -10.5mm:

Therefore I'll have to adress the offset (0.1/-10.5)

What I want:
The homing procedure and the pick up of the tools (four toolheads, tFreeN.g, tPostN.g, tPreN.g) should be performed relative to the global coordinate system (without the offset of the z-probe)

The true auto bed leveling (G32) and the mesh bed compensation (G29) should be performed with the offset active of the z-probe

The individual tool-offsets are measured to the center of the carriage as well and not to the z-probe. The Z-offset of course is relative to the z-endstop trigger point (0 when triggered in the homing position)

How do I proceed to setting up the individual coordinate systems?

My assumption G53 is my global coordinate system and therefore like i mentioned earlier in the center of the bed and center of x-carriage. Next I have the second coordinate system like G54 with an active z-probe offset to perform G29 and G32. The third coordinate system will be active after picking up a tool (corresponding tool-offset set in config.g)

Thank you in advance.

Best
Simon