Is this the problematic "stance of the Belgium authorities on the existing services" that you were referring to? Or was that something else? I'm curious because I'd like to understand what the difficulties are on running new services beyond Brussels.The problem still exists; checks are performed at the UK end, but it does not prevent people reaching the UK before being checked.
I also didn't experience any checks at St Pancras recently (in the last 12 months) when travelling from Brussels. As far as I know, the Lille loophole problem has been solved with the new arrangements in Brussels and on the train for travellers to Lille. Do you know differently?