Space between lyric elements?

My plugin adds some annotations to the score as lyrics. I'd like to make sure that there is always some space between each annotation (individual lyric element), but when space is tight, Musescore puts them right up against one another. I could simply add space characters to the start and end of each element, but that doesn't work for me because some elements are underscored and the underscore extends under the space (I don't think there is any way of underscoring just part of an element?). I've fiddled a bit with paddings and margins on the element, but they don't really seem to be honoured - although I could just have made a mistake. Should this be possible? Does anyone have any suggestions?
Many thanks
Paul