If someone is using optional packages that add markup such as underlining to code, and the markup is so prevalent that he needs extra line spacing, he is advanced enough to know how to adjust that.
Line spacing preference is idiosyncratic, and spacing varies by face as well. I propose adding an Org customization settings to adjust Org's line spacing, so that noobs can more easily achieve legibility. Adding a function that hooks to Org is too complicated.
