Can Two Fonts (hieroglyphs) Be Stacked On The Same Line In An ePUB?

Windows 10 64-bit, InDesign CC 2107

I'm assembling a reflowable ePUB 3.0. for iBooks, which contains hieroglyphs, using the JSesh true type font. In some instances throughout the book, these characters are stacked, one on top of the other. I'd like to keep these as live fonts, but have been unable to come up with a way to do this. My first attempt was to create a small, single row, 2 column table, but regardless of size, the table loads on the very next line. I need it to stay on the same line as the text before and after, like it's all part of the sentence. Then I tried converting the two fonts to outlines, grouped them and inserted them inline. This does work, but they get converted to PNG upon export, which means the color can't change if iBooks' background is changed (ei: black bg - white text). Then I tried using a separate CSS to adjust the baseline, via span tags, just to see if I could get the font lifted upwards, but iBooks is ignoring: baseline-shift: 0.5em;

Any ideas? The 1st screenshot is how it looks as fonts in InD. The 2nd one is after converting to outlines and loaded inline, which is how I need it to look.