
I haven't changed defaults to get my subscript 1 taller like yours, but the point is: The image is in the Dimension text editor, and the little white thing between the lines of content is the text cursor in a line between the other two that is set for a tiny text height, and has no character content. You can experiment with a text height for that intermediate line that will give you the effect you want.
EDIT: Here's the text-content entry in entity data for that:
(1 . "Q{\\H0.7x;\\S^1;\\H0.07937x;\\P\\P}TEST")
The red part is the tiny-izing of the text height for the middle line [which is actually imposed before the carriage return that makes that middle line, which is the blue part]. The two \\P entries in a row are the two carriage returns, with nothing between them being the no character content of the middle line.
Presumably a routine could be written that would define a command that would just impose the red [with some appropriate number] and blue parts into any Dimension text containing a carriage return that you would select -- all you would need to do would be to pick the Dimension.
Kent Cooper, AIA