Actually you can, well sort of.
As long as you know the forum nick of the developer(s)
On the right side of the thread listing, Where it says the number of "Replies" if you hover over it it will tell you how many posts you have in a thread (for example this will be my 111th post in this thread), however if you click on the actual number it it will list everyones post count in that thread (for example I see Redralph has 199 posts), if you then click on the number of posts to the right of the persons name it will display every post by that person in that thread.
Do that for the Dev whose comments you are interested in and it is pretty much what you requested. Kind of convoluted but an interim solution for those interested.