Depending on how they define 'safe standing' I would back a trial. For me safe standing would have to be 100% no risk of the crushes we had in the past, and no risk of being blocked in by supporters either side. It would also have to be as safe for small children, pensioners and the disabled. Yes that is a challenging standard, but we all know what happens when corners are cut on crowd safety.
They are thinking of leaving the seats in place,withe a metal framework attached to the back of each seat, like a barrier, and if everyone is allocated a seat there would be no crushing, would have to be in a specified area tho.