Hello,
The problem is that all these things are super-specific to individual setups - hardly any tool changer works the same. We recommend our partners - just had a meeting about that a while ago - to define a KRL function with all the logic and to put a defined axis position before and after the Custom-KRL component.
That way, even though the tool change is not simulated, the simulation is still accurate.
Regarding the tool length measurements that shouldn't be too complex:
Measure the triggering position of a pressure switch with a very short tool.
Move the new tool in a very safe distance (> longest tool) over the switch
Enable an interrupt with the switch
Move the robot downwards until the switch triggers.
Stop the robot
Use the Z-difference to the reference tool to calculate the new XYZABC values
It only gets a bit meaner if the tool is mounted with a strange orientation, then you need to do some trigonometry.
Best,
Johannes