Upon further checking, the setting the Commit field via Workflow is a current system limitation. I’ve found several related cases to this and they’re attached to an enhancement. This is logged and being tracked under Enhancement 498309 Sublist Action Group to Set Field Value in Sales Order Item Sublist > Commit Field Unavailable in Field Options
Tag: Do not commit
Supply Allocation feature & “Do Not Allocate”
When the Supply Allocation feature is enabled “DO NOT ALLOCATE” showcases the same functionality of “Do not Commit” in Sales Order. By setting “DO NOT ALLOCATE” in back-ordered item lines, whenever stock comes in the future it won’t get committed in these Back-ordered lines.