When are you releasing this update?
We cannot release any updates right now. There are big software updates coming out soon, and we redid our Live Update method, moved on a different server, and some required updates are not even dependent from us, but we are not a the liberty of discussing them right now.
Be sure the next GSX update will be very significant, because it will include lots of improvements that (due to the above reasons) we couldn't be able to release as immediate fixes now.
Also, I've noticed that when flying into FSDT / Flightbeam Scenery along with an active GSX, I get severe pauses as I approach the runway/field. This is particularly bothersome with PHKO, PHNL, KMEM (really really bad - not friendly at all), KFLL, and KSFO. Is this a communication bug between the applications?
There's no bug whatsoever, it's just your system is overloaded by other application communicating with Simconnect.
Its not as severe with any other scenery that does not use Couatl
The "not as severe" comment seems to indicate you do SOME stuttering, in other sceneries too. There are several 3rd party addons that place a significant communication strain over Simconnect, with weather engines being the most demanding.
Couatl is JUST another Simconnect client, and it doesn't add much, and it surely doesn't add any strain, when GSX is not active but, of course, if the Simconnect communication channel is ALREADY clobbered with those other applications, adding one more might just be the straw that broke the camel back, as they say so, you can be easily mislead thinking Couatl is the cause, when it's not.
Another thing that can cause problems are exceptions, communication errors, and if you enable the Simconnect diagnostic mode, it's possible to check which addon is causing them and, all users that reported such issues and assumed they were caused by Couatl or GSX, in ALL case when we went down and did the actual troubleshooting, it always turned out the exceptions and errors were caused by other addons.
However, I still get pausing when flying into the likes of Flytampa with GSX active (perhaps loading in the GSX info).
The only thing GSX does when you are flying, is just checking which airport is the closest to you, so it's not really possible this would have any impact, since it's a very light request, and it's not even made constantly. But again, if you have other issue already, it's possible they might stall the communication with GSX, so you are again being mislead it might be a problem caused by it.
Can we anticipate a better performance based update to this matter on this next release?
Since there are no performance issues in the first place, it will be difficult to say if you will see any improvement, since this is clearly something that is happening on your system only.
I can only say that, if you would like to try a Teamviewer session, I might have a look at your system, and see what's really causing the pauses.