Likewise, ozbeck, I would always make contact if in the vicinity and advocate good airmanship in having significant margin of error as you suggest, however the point I am questioning is whether there is a requirement to get clearance to penetrate a MATZ? I agree it would be poor airmanship not to request penetration, however it does change the legalities somewhat, especially if there was inadvertent descent.
As you say, the requirements, as posted by Talkdownman, are not necessarily the options all will be comfortable with.