I’ve started porting interactive_markers to ROS 2 and taken this as an opportunity to revisit the design.
One of the proposed changes is to use a ROS service, instead of a latched topic, to communicate the full state between an interactive marker server and client. The consequence of this change is that it will constrain us to one interactive marker server per topic. In ROS 1, it is possible to have multiple interactive marker servers interact with a client on the same topic, but it is unclear if this is a common use-case (it doesn’t seem to be).
If you have feedback on the proposed changes or other changes you’d like to propose, you can use this GitHub ticket.