If unchecked, which is default, plugin will not use instance weight information to scale the number of executors per node. Instead, Jenkins will just use the number of executors defined in configuration field Number of Executors.

When checked, the plugin consumes instance weight information provided by a Launch Specification and uses it to scale the node's number of executors from configuration field Number of Executors. Note: current implementation doesn't support Launch Template, only Launch Specification.

Example (here instance type from launch specification matches with launched instance type):
Number of Executors Instance Weight Effective
Number of Executors
1 1 1
1 0.5 1
1 0.1 1
10 0.1 1
1 1.5 2
1 1.44 1

Plugin always set number of executors to at least one. If the launched instance type doesn't match any weight in launch specification, regular number of executors will be used without any scaling.