take this as constructive criticism, not an attack.
Undo feature in CTF 2.5 is really bad and with that I mean it. I often lose time just because I can't use its Undo feature. Imagine cases where I need to run test app to verify something but after I need to make undo steps, I can't. Simply because UNDO is no longer available.
This is a huge time sink and very uneffective. Because after this I need to re-code the steps manually again.
I hope F3 won't have these issues. All the best