The people dishing out research grants aren't exactly keen to have greater scrutiny on PACE.
I think we need to remember that the head of governance for the MRC went out of her way to back PACE. She dismissed complaints about outcome switching and she appeared in the information tribunal to stop data being released. The MRC and in particular their head of governance have been seen to be lacking. I don't think they will be keen to take up this issue either.
Perhaps when the MRC is gone and the research councils are merged we may get an organisation willing to actually check on issues with the research they are paying for.