What I'd like to see is some kind of "shorthand" option, like asterisk for bold and underscore for italic, that would increase or decrease the font-size of the surrounded text by a specified number of "steps" of the font size list.
For example, something like the escape slash used for newline followed by a positive or negative number to indicate the steps. So
<strong>text</strong>would increase the font size by one step and
<strong>\-2text\-2would decrease it by two steps.
Or maybe use slash+circumflex to go up one step:
And slash+v to go down one step:
with multiple circumflexes/v's to go up or down more than one step:
To start the internal string with a circumflex or a v, insert a slash to escape:
Increase Font-Size of the word "very":