Is item attribute standard lot size used for lead time calns

We are on 12.2.3 and use Oracle Inventory module.We want to set the value for the field standard lot size under the costing tab in the organization items screen so that when costing our costs account for lot basis susbelements and factor in this lot size for the items.

However we do not want this standard lot size value to affect our lead time calculations (we are keeping the lead time lot size field as blank.In testing when we ran the calculate mfg lead time and rollup cumulative lead time programs from BOM resp ,we noticed the lead times used the default lead time lot sioze of 1(and not the standard lot size in the costing tab which was other than 1).This is what we want however the invenotry user guide says that when the lead time lot size is blank, the system uses the standard lot size for