For my point of view, just like the FTDK said in response to my deleted post. Contact EARLY so you can get where you need to go when you get there. There is zero possibility of getting A LANE...meaning no clearance required anywhere on the coast over or near Willie. Just as much chance as getting a lane over the top of SY...just like in the US.
If the overhead route was available thirty years ago and was marked on the maps...which means available on request...wouldnt a prudent thoughtful pilot ring the number in the book...knowing from the ARFOR the wx would be crud inland...to request that route? I am pretty sure the PIC would not have planned inland...however, going by the transcripts, somewhere on that track he would still have had trouble with wx closing in in the CTA.
I feel issues between ATC and VFR pilots is perceived skill or lack thereof. Nothing to do with whether Mil or Civ just worried VFR will go pearshaped right in the middle of busy airspace and then have to be extracted by using a huge amount of committed resources. And that issue has been extant since VFR and IFR became separated as airports got busier. Trust!