Does Gazebo's world snapshot restore plugin‑internal state such as ROS node handles?

When using Gazebo's world snapshot feature to pause physics, serialize the simulation state to an SDF file, and later restore it, the primary goal is to confirm that all relevant simulation data—including model poses, joint states, and any plugin‑internal information—is accurately recovered.

The default snapshot mechanism captures only SDF‑defined elements such as link poses and joint velocities; plugin‑specific data like ROS node handles, internal counters, or sensor buffers depend on each plugin’s own reset implementation, which may or may not fully reinstate the pre‑pause condition. This leaves uncertainty about whether restored plugins behave identically to their original state, especially when tolerances are applied only to measurable SDF fields. Does the restoration process reliably reinstate plugin‑internal state? Are there known gaps in the snapshot that require plugins to expose additional serialization hooks? What verification methods can detect discrepancies in plugin‑specific data after a restore?