The purpose of that feature wasn't to enable direct trial data editing, but to let Unas debug possible problems with the save system. Only Unas can say why he decided not to restore that feature in v6, but having looked at several trial data files in v5 and v6, I'm fairly sure the reason is because v6 is far less likely to have those kinds of errors.
I'm not sure why this was removed in the v6 editor, but you're looking for this
Please, look to see if a similar topic has already been started before starting a new one. "How to clone a v6 trial" questions have been asked and answered
[D]isordered speech is not so much injury to the lips that give it forth, as to the disproportion and incoherence of things in themselves, so negligently expressed. ~ Ben Jonson
Current AAO Development Priority: Issue #94: Grayscale Mode