It all depends on what you are trying to do. In my situation I only do TCP/IP And UDP in the pronto. I use no extenders. I have my own "Extender" in the form of a server program running on a PC.
I therefore want the capability to receive and respond to external devices using TCPIP or UDP. I believe the current implementation with Jon's changes does a reasonable job but may have issues with multiple responses when each ends with a CRLF sequence. (Have to remember to speak to Jon)
I would also like the option of registering a stub with the simulator (written in some sensible language) that the simulator would call when a TCPIP or UDP sequence was issued. I get around that today by having a setting in my TCPIP library to simulate a result via table lookup. in that way I can "Simulate" various responses from a device I do not own. The stub would return an expected response to test out the logic without the need for the physical device.
When doing complex TCP based IO with poorly documented external devices you always need the physical device sooner or later!