Recently I created a small project rt_logger to log generic data (e.g doubles, std vectors and eigen vectors and matrices) trough real time publishers rt_pub.
To see how it works check out this test file.
I hope this can be useful to have a quick and simple way to log numeric data from real time controllers. In the future I intend to extend the project to support more data types.
Besides the publisher, which you already have, we have some integrations for storing and displaying the data for short term (PlotJuggler) and long term (Graphite/Grafana) which may be useful to you.