Make to Order functionality Clarification

HI OPM Gurus,

I need a clarification on the Make to Order Functionality:

1st Case;

Sales Order is created for an Item(product) which has a demand of 6 Case.

Make to Order Rule is set accordingly specific to Org and "Check Availability" feature is Enabled.

On Hand stock is 2 Case.

Now after submitting the request, Batch is not created as there is some stock available to meet the partial demand.

2nd Case:

"Check Availability" is Unchecked.

On Hand Stock is 2 Case.

Here after submitting the request, the Batch is created for 6 Case to meet the Demand and will not check any stock availability.