MOSS 2007 had Stsadm get and set property commands to change the workflow config settings.
In SP 2010 using Powershell it is Get-SPFarmConfig and Set-SPFarmConfigExample:
Set-SPFarmConfig -WorkflowPostponeThreshold 30
Verify the configuration is set by Get-SPFarmConfig as shown in image above.
Here is more info on these:
http://technet.microsoft.com/en-us/library/ff607962.aspx