Sorry Mr Evans, but you already have 4 London rotations a day within the IOM airport hours, (albeit 3 LGW & 1 LTN).
I don't think IOM airport would need to stay open until 10 o' clock as you claim to have asked the IOM government to provide for to enable a 4th LGW rotation. How about rescheduling the first rotation 20 minutes earlier and then 4 LGW returns could easily be accomodated if you wanted to Hmmm ??