Fiona, while I have agreed with you initially, it is probably really fair now for me to tell you that it was a decision I never had to make, and I am not speaking from any form of experience.

I had 6 VBs, all intact. I damaged the pelvic floor muscle with Diva by being impatient though (to avoid a cannula) and pushing before I was fully ready to. That is, I was pushing fully during those contractions that you can hold off on for a bit, iykwim. They are just meant to be little nudges to move babies head down and help with dilation, but he was putting holes all through my damned arm!! So the best advice I can give is to listen to your body and go at its pace.