With all due respect to Margaret Aspinall, she is just the figurehead, and spokesperson of the group.
You'd have to convince dozens, ney, hundreds for any chance to change their stance.
Thats never going to happen. They are too set in their ways to even consider another option, regardless of what that option is.
As long as the word 'standing' is in there, then they collate standing with unsafe, regarless of the situation.
You'd be better calling it 'safe not sitting', than safe standing, as the word standing is met with fingers in their ears and going lah, lah, lah, lah, lah, so they don't have to give an answer that they don't like.