Greetings. In optimistic locking, if a case is opened by two users at same time, when user 1 commits first whilst user 2 is editing, and when user 2 tries to commit, he will see a conflict message asking to refresh the screen but whatever user 2 is doing will be lost when he does that, any way we can save user 2's work before refreshing?
No, you cannot. That's the whole point of optimistic locking. Whoever commits first wins. The other user has to refresh, see the changes committed by the first user, decide whether the changes he/she was doing before the refresh still holds good and then choose to commit or cancel.