Thanks for those thoughts - but a query: whilst an inexperienced IFR pilot, I'm not a complete beginner and my experience has generally been that I have been given a handover on long trips across the UK, IFR in class G. If ATCers are going well beyond their required standards of service, then I'm grateful and have presumably been lucky.
This experience was so far the exception for me: I generally have been given either a handover or (less commonly) a warning of cancellation and/or request for my intentions. It's worked well, and I felt I was indeed getting a Good Service.
In this particular incident, I also got a Good Service, which I felt enhanced my safety and reduced my workload. I had a VFR plan, and like all good pilots that was down on various bits of paper in front of me, it didn't vary much from doing it IFR really - just a change of altitude and service requested.
Frequency plans however are of marginal usefulness - I'd already abandoned mine as the international airport I'd hoped to get a service from I couldn't get 2-way with, going with the switch to the regional airport I was talking to. From there the obvious next frequency to me was not the one that had just been suggested to me. This is pretty normal flying around the UK; a lot of flexibility is needed, and depending upon their own requirements controllers will often ask you to switch frequency / service and a LARS controller is often not the best provider if you are very close to a particular airport's CAS.
My sole point really was about the method of termination of the Good Service I'd been receiving, which at the time flustered me a little for the couple of minutes it took to adjust.
For the record, I'm really glad I posted in here, the learning points have been, and continue to be, very valuable. Breaking my VFR-touring mindset of avoiding CAS and instead going into it being perhaps the latest.
G