RichTextEditor and email signatures

Is there any way to compress text (line height) in the RichTextEditor such as say an email signature? Every time I press return or even shift-return it creates a new paragraph rather than a br. Any suggestion on how to compress the text to make an email signature look nice would be appreciated.

I do see it’s offered as a feature of the enhanced RTE but it’s marked as experimental.

Also the shift-tab feature didn’t seem to work, even in the online demo linked from the addon directory.