I think that maybe a letter (or several letters) to EASA outlining in a vey objective manner the practicalities and benefits of using hand-held PLBs within the aircraft as opposed to fixed installations may be in order, together with a request for an EASA approval to carry said PLB in aircraft.
This may then have the effect of obtaining an EASA approval that will overrule any CAA 'non-approval'.
Any views?