I am the developer of JReviews and we recommend your extension to clients as the most viable solution to create a multilingual site. However, more and more clients come back to us telling us that some parts of JReviews are not translated and that your reply is that we should change our code to respond with HTML instead of JSON. I read some other posts here where you say the same thing.
You already intercept the request response so you could convert the JSON object to an ARRAY, then translate the values in the array. You could even go as far as letting clients specify which "key names" in the array should not be translated, and to take it further you could let clients specify which types of JSON requests based on URI format should be translated and which left alone.
As developers of a very complex product for almost 10 years now we don't see how moving towards 100% responses in HTML is the future and we are not able to re-write our code to move backwards. On the other hand, we believe that since you are in the business of intercepting responses and manipulating the data you could probably provide added value by also supporting the translation of requests that return a JSON response.
I hope that you seriously consider this as it could further improve your already great product and make it 100% compatible with all extensions. Maybe there are technical limitations as to why you can't translate JSON and if that's the case it would also be good to know exactly what these are so clients understand that the limitation is a technical one.
I tried to find a contact email no your site to write to you directly, but I couldn't find one so forgive me for posting this in the forum.