I tried out loading a font into the font folder and indeed it was very easy. (Just need to close GameTranslate before and open GameTranslate after.)
And here is the result :

From your description, I really was expecting far worse!
I feel that one part of the issue is a font size problem as OpenDyslexic tends to be pretty large.
When I see the
“ 1920 x
1080 “
I feel it’s trying to fit the text into the frame and has run out of horizontal space.