If you look at the History log post here, I noted what I had to do and the 8x12 font harvested out of the PC-FX BIOS actually works nicely.
Oh, darn! I hadn't seen that timeline before, thanks.
Sorry, but if the original developers limited themselves to 8-wide glyphs (Hiragana and Katakana), then it's really, really unlikely that they used the 4-pixel text-coordinate step that makes the bi-width font an "easy" hack.
Perhaps they did ... but I'd be very surprised.
Both Team Innocent and the Xanadu games originally used 4-pixel steps because they chose to deal with the 12-pixel wide Kanji ROM font that meant that alternate glyphs would start on a half-tile boundary.
It would probably take a pretty major hack to use a bi-width or VWF font in ED.