No problem .. my default idle refresh in the setting is set to 10 seconds.
The trigger is below ... It's a separate Trigger
Action = Set Market's Idle Refresh to
Rate = Random(67)
Selection = First matching selection
no more often than 10 seconds
Market status = idle or suspended
Conditions are met
Selections trigger expression idle_rate is less than 15
~~~~~~~~~~~~~~~~~~~~~~~~~~
So every 10 seconds or so, the refresh rate is set to a random number of seconds between 0 & 67. Should the number be less than 16 ... the trigger will try again .. until a random number above 15 is generated.