[TYPO3-workspace] Workspace to Workspace swapping/publishing

[Mumpitz Master]

At the moment i have have two Workspaces, LIVE and Preview.

When i create a Preview-Link for the Preview-Workspace i cant work on the project, cause the customer i sent the link to would see my changes that could break the layout of the page.
As i experienced, the stages that are part of the extension do not prevent this.

What i need is a third Workspace (Develop) where i can work on, while the customer can have a preview on already done work, without doing things twice or affecting the LIVE-Workspace.

If i am ready with my work i would "publish" it to the Preview-Workspace to be able to send a Preview-Link to the customer. If he is then fine with all the changes i would really publish the Preview-Workspace to the LIVE-Workspace.

So there will never be direct changes to the Preview-Workspace, they come from the Develop-Workspace every time.

My Question:
Is this behavior possible with the current extension or with an additional extension or is there a totally other way to achieve this?

I asked this Question some time ago on StackOverflow, but there are no answers to it yet. If there is no possibility, i would like to suggest it as a new Feature for future Versions.