Localhost configuration with MicroROS and CycloneDDS

I'm working with CycloneDDS for ROS2 Humble and I'm trying to use the ROS_LOCALHOST_ONLY variable (or another localhost configuration) with MicroROS. While it worked with FastDDS, I haven't been able to establish communication between the agent and the ROS system using CycloneDDS, even though both are running on the same machine.

The (serial) connection between the agent and the microcontroller is successfully established, and all instances (subscribers, publishers, etc.) are created without issues. However, the topics are not visible in any other terminal on the machine.

Everything run on Ubuntu22/Jetpack6.

Is there an option to enable this configuration or will it be included in the future?

Start by reviewing how ROS_LOCALHOST_ONLY and CycloneDDS are configured for the micro-ROS agent, comparing the reported setup with the working FastDDS case. Reproduce the Ubuntu 22/Jetpack 6 setup and check whether agent topics become visible from another terminal; done means localhost communication works with CycloneDDS or the supported limitation is documented.

Written by the indexing model from the issue text.