Thanks ThePony, that's exactly the approach I intend to take.

I'm also very glad of all the supportive people on here as I am concerned that I'll get things wrong one way or another! I'm very lucky in that even though he's on full livery my YO has been amazing about changing things around to accommodate his needs now. Considering how tough it was to go against the grain initially I can't believe how lucky we are that the people involved in his care are being so helpful.