Hello...
in our taxi procedure...we check the stby compass against the IRS heading on PFD/ND/DDRMI.
we also do that in our T/O breifing while while on the gate
in the MEL ...the stby compass can be inop provide the 3 irs's are operative.
so my question is ....is it really required to do that...i know it is not an airbus sop.
what is your idea.
thanks