Interesting, Cathar.
Each Contracting State undertakes to insure the prosecution of all persons violating the regulations applicable.
The question is whether the local-airspace penalties also need to be enforced (by the country of aircraft reg or of the pilot license). I am sure the answer to that is NO.
For example, the penalty in France for busting one of the nuclear TRAs is something silly like Euro 10,000 or aircraft confiscation (no reference; this is forum rumour). I don't see the UK CAA confiscating the plane on behalf of the DGAC. It is slightly more likely they would fine the pilot Euro 10,000 but again unlikely; even high profile widely publicised busts like the Eastbourne one (which caused a real problem) drew a much smaller fine.
Busting some UK TRA by flying a few hundred m inside it horizontally, or 300ft too low through the top of it, isn't likely to result in such a fine even if prosecuted (which is itself unlikely).
The business of confiscation is also fraught with problems, IMHO. If Joe Bloggs owns the plane and does the bust while PIC, it's clear. But what if Joe Bloggs lent/rented the plane to the pilot? Under UK law, the plane would not get confiscated then (AIUI). Then you have Joe Bloggs on board but not PIC at the time....