Cheerful news. CA including Britline, have updated their policies to allow far greater amounts to be transferred from your CA accounts - without having to fill out a form..
Transfers up to €2500 are the default. You can (temporarily) raise your transfer limits to 10000 within the Ma Banque app. Limits can be (temporarily) raised up to 100000 via a call to CA, after tapping in 6 digit code and account number. Over 100000 there is a form required and security checks undertaken.