How to disable an Explain Plan completely in PA (41791)

How to disable an Explain Plan especially if it takes a lot of resources

You can exclude explain plan completely by doing the following:
Open the Agent Administration | Performance Repository on left panel | Change Tracking. There you can configure the change tracking and you can exclude the Execution Plans by unchecking explain plan.

Note that Explain plan is one of the repository activities which is part of change tracking so if this is something you may not necessary need then you can exclude it. However, if explain plan becomes relevant to your operations then you may want to just change loading times to a less active time to reduce network traffic. In order to do that:
Open the Agent Administration | Performance Repository on left panel | Change Tracking and then change times under 'scheduling'.