I am not really sure if it was much better, I think it is better but am not sure it was worth all the extra work weaving it in and taking it out again.
I left the yarn in at the bottom and just worked it down off the warps. (I had unpicked the higher bits as they went in and out of the outline of the shape.) It was quite scary taking the last of the waste yarn out - I realised how easy it would be to pull the warps out of your weaving.
Then I decided to get a start on the sewing in of the warps. I did this while watching tv - a mistake!!! I wanted to get started quickly as I had a couple of spots on the shape that were wider than the bulk of the weaving (marked in red in the bottom picture) and I didn't want the warps to be pulled through accidentally. (The other warps travel through to the various parts of the tapestry and appear more secure.)
But then I got involved in the show and just kept sewing it, totally forgetting that I want to pull some of them through to make them long enough to sew into the oddly shaped bits (marked in purple). So I will have to have another go tomorrow and undo the sewing, then pull them through. Let's hope it all works out and doesn't start undoing the weaving!