When your development branch is not up to date SourceTree won't let you create a new feature branch even if you select "Working Copy Revision" as your starting point.

As a result, the user has to close on three dialogs to go back and pull the development branch and then navigate back through the dialogs to try again.

Expected behavior:
1) SourceTree shouldn't care about the state of the development branch when you are creating a feature off of the working copy revision if it is not the development branch.
2) If the current branch is out of date SourceTree should just prompt the user and ask if they want to pull the latest changes. Most of the time (when there are no uncommitted changes) this will be sufficient and will save the user the hassle of having to close and reopen all the dialogs.
3) If neither of those first two solutions are available SourceTree should warn the user that the development branch is out of date as soon as they click "Start a New Feature" instead of waiting until the user has filled in the feature branch name and clicked "OK".

To Reproduce:
When the development branch is behind the remote branch
1) Checkout a non-development branch like a feature branch or hot-fix branch
2) Click Git Flow
3) Click "Start a New Feature"
4) Click "Working Copy Revision"
5) Type a feature branch name and click OK
6) Feel the pain