I think the scenario you are testing is really complex, and it is hard to extract any conclusions regarding performance.
A couple of months ago you were recommending to switch to OpenSplice and this time OpenSplice often shows start-up times higher than 10 min, according to your blog post.
In such a complex system, with components that are right now on development and have problems using any DDS implementation (see for example https://github.com/ros2/rviz/issues/437), I think the best approach is try to isolate the issues and understand the reasons behind the numbers/hangs you are getting.
Because the symptoms you are describing it seems you are probably losing discovery multicast announcements. Multicast is not very reliable in some wifi routers, and take into account the discovery announcement period is 30 seconds by default in most implementations. This could lead to long discovery times. Could this issue also produce timeouts in your scenario? You said just re-starting the rviz solves the hang issue, and this could indicate that is the case.
In July, we contacted you through email offering help to debug these problems, and here I extend the invitation. Let’s have a meeting to discuss how to isolate/reproduce the issues.