last time they broke in by removing the roof tiles off the roof as its impossible to attack the doors for entry from the outside
That to me suggests you are now a known target, that they judge the risk of being seen clambering about on the garage roof worth the reward of posh bikes inside…
Other than the garage contents, how outwardly visible is your cycling habbit? Carriers left on cars? Stickers? Kit on show anywhere? Regularly ride past scummy areas on the way to/from home?
As a physical prevention could you fix sheet steel or bars to the rafters under the roof? Eventually gaining access becomes too difficult and they’ll give up, multiple PIRs is a good call too, if you illuminate the buggers they’re really not going to be keen on hanging around…