It should be possible to reassign an agent-initiated node to a new APE or HA pool using the Solarwinds API or the GUI. I recently had a failure of an HA pool (both active and standby servers failed) with dozens of agent-initiated nodes. It turns out you can't reassign the agents to another HA pool or APE because the agent has to check in with current polling engine. The only fix is to resurrect the failed HA pool/APE or reconfigure/reinstall the agent on the monitored node. This is impractical in terms of time and effort in many environments.
