If anyone wants to help, I plan to port PlotJuggler to ROS2. Any help from people with experience in DDS/ROS2 is welcome.
Is there any plan to port rqt_multiplot?
There is no reason to implement “yet another” plotting plugin. There is already (at least) two:
rqt_plotas well asrqt_multiplot
If it were quicker to do it from scratch, or just narrow support to a single back end, and that would make the difference between having rqt_plot by the desired time or not, and/or it would end up with better performance, then that would be the reason to consider not just a direct port.
This is the only thing I have to say about the latter comment 
