If it's good enough for the BBMF Lanc, Spit, and Hurricane in formation it's good enough for any GA pilot.
As part of the same formation maybe, but to fly formations at low level and at high speed is the very reason why I would avoid that corridor, as I would be unknown to yourselves and we will not see each other until the last few seconds.
Inside controlled airspace you receive traffic information or separation. Outside that you are on your own to see and avoid. But how to avoid if you fail to see?
The limitations of see and avoid are clear: Traffic information should be issued to allow pilots to conduct a directed search.
Why not fly a more direct route through controlled airspace instead?
In this case it is clear which I would one I would prefer any day.
I would only use that corridor if I have no real alternative.
As far as "minimum safe altitude" goes, that term doesn't exist under ICAO.
That doesn't matter. At low level: In hazy and poor VMC it's wise to obtain assistance to avoid obstacles and in good VMC conditions it's wise to obtain assistance to see and avoid other traffic.