Functionality of Modify option on auto create form

Hi experts,

From Purchasing user guides I have understand Modify option on auto create as:

When encumbrance on requisition is ON "You can only modify the quantity on encumbered requisition lines".

When encumbrance is OFF and If the profile option "PO: Restrict Requisition Line Modify to Quantity Split is set to Yes you can only modify the quantity.

But in my case it is allowing modification in:

* Profile option "PO: Restrict Requisition Line Modify to Quantity Split is set to No

Line Type

Quantity

UOM

Price

Account

Need by date

If we are allowing such line modifications in practice then w