Here's an undocumented feature I just discovered accidentally: You can adjust the distance of text on a path by holding down the Ctrl key while you click on the text. The text aquires handles. Then click again and drag it toward or away from the path. An arrow appears showing you where the baseline will be when you let go. I just checked the Draw help files and this feature isn't in there. (My apologies, however, if this has been around since Version 1 and I'm the last to find it.)

(Incidentally, while I'm on the subject, you can also interactively move text side to side on the curve using the Node Edit tool. Use that tool to drag-select all of the nodes of the text and then drag any node right or left. Text on a curve will actually follow the curve as you drag.)