How do I get Labels & Addresses to automatically downsize some longer addresses so they fit on the label?
Labels & Addresses does it automatically when you print addresses, if the address doesn’t fit on the label. You can see how the address will look like in the preview area of the Print dialog. Downsizing makes it more difficult to read the address, so, when possible, position the address so that there’s enough space to the edges of the label or envelope.