Having xacro arguments for odometryFrame and robotBaseFrame within diff_drive plugin will allow to set these while launching multiple robots using multi_turtlebot3.launch so that each robot will have its own odom => base_link frame broadcasted by gazebo.
TurtleBot3 platform used - Burger
ROS distro used - ROS 1 Noetic Ninjemys
With reference to this https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/214
Having xacro arguments for odometryFrame and robotBaseFrame within diff_drive plugin will allow to set these while launching multiple robots using
multi_turtlebot3.launch
so that each robot will have its ownodom => base_link
frame broadcasted by gazebo.