How to default the 'Allow Partial Shipment of Lines' flag to 'No' for specific Business Units?

We want to default the 'Allow Partial Shipment of Lines' flag to 'No' at line level, for specific Business Units, on order creation. We tried using Pretransformation Defaulting Rule for Sales Orders but that is having an impact on other areas such as the Sales Order header details are not getting copied to the line level since the system already considers the lines to be overridden due to the defaulting done through the Pretransformation Defaulting Rule.

We then started exploring defaulting through Page Composer (sandbox). But through Page Composer, though the value is getting defaulted to 'No' at the line level, we then cannot change the value to 'Yes' for any of the lines if we want to, by overriding the lines.