Greetings,
What about, When the 'Hebrew Audio Add-in' is Published, having the ability to have it (just the way it is, nothing extra necessary) read the 'In-line' transliteration words under your English text (the already made 'Greek' add-in for the NT of Course
, with the text lighting up with the 'Highlighter' of your choice? I know a lot of people have asked for a 'Read Out Loud' feature, and since this would be to taxing, and time consuming for Logos to do at this point, I thought maybe they could use that which is already created... Just link them, and push Play! 
This would be biblical Greek and Hebrew of sorts but it's a start.
Let me know what you think?
***If this got hot they could make an English add-in later (this couldn't be as hard as it has been for the 'Hebrew' add-in considering we already speak this language 