I would be very worried about refusing higher duties unless directed to by the association as part of PIA.
It is part of the normal duties of LAME & Snr LAME especially if on the same day & shift.
You would have to have a real good excuse to say no to it, then continue working as a LAME.
In fact, by doing the higher duty, this takes a LAME off the floor and
further reduces the workforce at the coal face.
If it required O/T or shift change, the answer is obviously, NO, I have plans made.
You don't have to bust your guts working just because you are doing H.D.
PS
take 5 (%)