Apart from Belgium and the UK there aren't many issues in keeping a 'foreign permit aircraft in European countries which are signatories to the 1980 ECAC agreement.
The aircraft does have to continue to be inspected by an LAA inspector - but that could be done by either returning to the UK or flying out your favourite inspector. The arrangements would be very similar to those of for instance certified D reg in the UK prior to EASA.
Of course it would be much better if the job preservation antics of the UK and Belgian authorities did not exist!