I haven’t used ROS2 much myself but some ideas are:
(1) Lots of topics from the ros2_controllers roadmap: Announcing the ros2_control working group
(2) Implement a ros_control controller that can accept streaming commands or trajectory commands, without the need to switch controllers. Similar to this PR but hopefully better. We would need to get the ros2_control maintainers onboard with this approach, though. It’s unclear if something like this would be accepted because it’s very different from the current paradigm. May involve splines or polynomial fitting. https://github.com/ros-controls/ros_controllers/pull/383
(3) Create the new version of jog_arm in ROS2. This is a local planner that plans at a very high rate (>100’s of Hz) so you can stream commands to the robot for teleop or compliance. It should probably be integrated with the MoveIt API better.
(4) Porting MoveIt Task Constructor sounds fine, too, but I wouldn’t be the ideal mentor for that.