I was curious if there will be a lot of rework needed to bring extensions and automation over to RTC 6.0. Here is what I have seen so far.
I found the time to setup my RTC 6.0 environment for Extensions development. This went very smoothly and did not differ to what I describe in Running the RTC Extensions Workshop With RTC 6.0. I then brought all the extensions, API and automation examples from my RTC API Development environment over into the new workspace in the RTC 6.0 environment.
I did not see any errors except in the code related to Contributing Attribute Presentations and the error can likely be fixed by using a different method. So although my API code touches a broad range of the API in RTC, there are only minor changes. The majority of the API seems to be very stable, since this was also the case when I brought over my code into RTC 4.0 some years ago.
There are likely additions to the API, but the API that is there seems to be very stable otherwise. This includes even internal API that I have used on some occasions. Of course, you still want to test that everything work after you brought it over.
I have to confess that I am so far doing the majority of the work in an environment based on RTC 4.0.1. The reasons are basically that RTC 5.x had an annoying issue as explained in Running The RTC 4.x Extensions Workshop With RTC 5.0.x. Since I did not want to put up with it all the time I kept working with 4.0.1 and only tested the result in different versions.
The RTC client and server API used in extensions and for automation seems to be very stable and there should be not a lot of effort required to bring over your own automation and extensions over to RTC 6.0
As always I hope this saves users out there some time and worries.