To be honest Timothy, I am amazed at how anti NATS route charges this has become (nowt to do with me guv!)
At the end of the day, you are an ex professional pilot, who displays expectionally good airmanship and ability. I am guessing here but you must spend a few £ keeping your IFR equipped twin and IFR rating current - not too mention lots of £ on a business trip from BIG-EDI. Why not use it!!
What's a few extra £ for an IFR departure, guaranteed radar service, a radar handover, and peace of mind.
I don't wish to harp on about push-on-itis and CFIT but there are loads of reports of low and high houred pilots getting it wrong - and keeping AAIB busy.
It's only money fella!!!