I get that to single space in the new editor you press SHIFT+ENTER but that doesn't work on mobile (android). How do you do it? My keyboard has the keys but SHIFT, I believe, is used for caps only so this does not work. 

On your mobile phone, go to the settings page and select keyboard -> options -> enter key -> allow shift enter. Then when you cant find that setting in your device because it doesnt exist, put the device down and type your message on a computer. Then the shift enter will work as expected.

Thats the only way I think will work. 

You could also create an editor button to let everyone add a line-break. 

@Kevin Carwile, thanks. I'll check that out for myself, but would hate to have to instruct all my members to do that.

@Ralf H., thanks. Neat solution, how would this be done? Maybe IPS can add it too.