Description of problem: Is it possible to indicate systems communicating over Jabber (osad-enabled) within the System Overview page?
I'm willing to review and accept patches for that. Of course, the System Overview table is already crowded now (and channel names wrapped to six+ lines) so care must be taken with the page design. You could make the list of columns configurable, for users to hide fields they are not interested in (like in cases when they don't use osad at all). As for the data source: for individual systems the information is shown in the OSA Status field in the Details > Overview page, which should give you hints as to where to find that information.
We did not have time for this one during Spacewalk 1.4 time frame. Mass moving to Spacewalk 1.5.
Aligning under space16.
I would suggest to make it its own page, similar to system currency or virtual systems. extra queries on main overview pages will likely cause performance issues for lots of systems.
Spacewalk project as an upstream for Red Hat Satellite 5 product is going to be End Of Life on May 31 2020. Spacewalk 2.10 has been released as the last release of this project. https://github.com/spacewalkproject/spacewalk/wiki/ReleaseNotes210 Any new feature will not be included therefore closing remaining RFEs to set expectations properly.