Since there is (according to my understanding) not even a requirement in the mentioned laws to have a Technical Pilot, there is, of course, no minimum qualification described anywhere.
Most airlines, however, use the installation of a Technical Pilot to enhance liaising between FltOps and Maintenance department, i.e. DDM / MEL issues etc.
The Technical Pilot can also collect vital details for trouble shooting purposes and give engineers a better understanding of inflight problems.
If there is a Technical Pilot position established in an airline, the FOM will (or should) provide details about the responsibilities and the tasks dedicated to him (her).
And why should a Technical Pilot not be "only" a First Officer? There are some right hand seat fellows who have a very professional technical knowledge and they may actually do a better job as some of the "upgraded" captains.... I know of at least 2 Technical Pilots who just collect the extra payments....no one would see any difference inside the company if they will be on vacation for the rest of the year.