I think you would need to do something at the start of path. This is where the tool axis has changed from the previous operation.
You will have to put this into first move event. (initial move only called after tool change, BUT you have to be careful if "Mill control" operation has the tool change but no motion).
Current tool axis is not available until initial/first move event.
"look ahead" (mom_nxt_* variables) also not available until then (well, they may be available earlier, but the values are bogus).
If you need the data earlier, you may have to write a separate post to read & save the first tool axis vector (or whatever) for each operation, then use that in the main post. Run this (using MOM_run_postprocess) at "start of program"
Production: NX10.0.3.5 MP16/TC11.2
I'd rather be e-steamed than e-diseaseled