Be careful of the 'cancel IFR' trick as well. If you cancel, and at
that moment are not the required 500 below the overcast, (controlled
airspace) you are instantly in violation.

I am intimately familiar with the SMX approaches, and can tell you that
there are at least some of the tower personnel there that seem to be,
well, difficult. Deliberately putting yourself in a position to be
considered violating a minimum altitude on an approach there while IFR
is an invitation for a legal problem. Better just to slow down and get
the flaps out so you can descend more quickly after you pass the fix.
Gene