Removing certain type of deliveries from scope of check in ECC ATP

Dear SCM Experts,

Some of our plants are not on gATP yet. It may take a while to get them moved to gATP due to various processes involved in those sites.

Now, the requirement is as explained below. We have the "include deliveries" option enabled in the scope of check. Now, suppose if we have 1000 pieces of Stock, the STO deliveries are consuming this stock and later when the sales orders are created, the stock is not being available and hence there is a sales order cut. What we would like to do is when we do the availability check for the SO deliveries, we wanted to exclude the STO deliveries from the scope of check so that we have the correct availability picture to get the SO delivery doc get confirmed. However, standard ECC ATP doesn't differentiate the type of deliveries. It has only one option "Include delivery" in OVZ9. Although we have different atp categories using which we can always configure the scope of check as per our choice this seems to be not possible in ECC ATP component.

Is there a work around for this ? Any custom solution recommendation is highly appreciated.

Thanks & Best Regards,

Babu Kilari