Drafting blind is a gamble: the line breaks that read fine in a plain text box can land differently once a real feed gets hold of them. A new Preview button beside the composer swaps the editor for a faithful mock of how each selected platform will actually show the note — X with its avatar, name, timestamp and action row, Substack with its note styling and subscribe button — updating live as you type. Flip back and your draft is exactly where you left it.