Orbits are Your Friend.
As pilots, we don't always know what's going on at the other end of the line!
Working Solent is certainly quite challenging jobs at times it seems...from both ends. My experience is that they are really helpful, providing you sound as though you know what you're doing, pick a sensible trajectory across their zone wrt their runway orientation and are ready to standby (orbit...) for a couple of minutes.
Plus, have a Plan B if they're too busy to accept.