When I flew for the military we were taught PHAIR - so you give initial call i.e.
"Fightertown Radar ABC123 (request MATZ penetration)"
"ABC123 Fightertown Radar pass your message"
"ABC123 a C150 overhead Glastonbury, heading 170, Altitude 2500' on 1012, routing Yeovil, Dorchester, Chard, requesting (MATZ penetration and a) FIS"
It flows well, and you can put the bit about the MATZ penetration either at the beginning, the end or if you really feel you must, at both sides...
It makes no difference to the controller when you mention it - as long as you give enough notice. MATZ penetrations, like entry into CAS are more readily obtained if not requested last minute.
You can fully expect to be told a specific route to cross the MATZ i.e. "MATZ penetration approved routeing north to south, 3 miles west of Fightertown at 2500'"