What puzzles me sometimes is when ATC say "Cancel STAR speed restrictions", often once I'm already below 10000'.
There may be further speed restrictions on the STAR, so this could apply then.
Where the STAR plate says Max 250KT below 10000, cancel STAR speed restriction should also cancel the general requirement in AIP for 250 below 10 - probably needs clarification.
I say Cancel speed restriction below 10000 and this to me cancels both restrictions.
If the aircraft is already below F120, I don't bother cancelling the speed restriction, except at pilot request or if aircraft is given track shortening.