Billing block variants at the Sales Order Item level

Hello to everyone,

Could anyone help me please with the following issue?

In our company we use Billing block functionality at the Sales Order Item level (VA02) to prevent billing if it's not allowed for some business related reasons. As you know, there are a lot of different variants for selection, but we usually use "Blocked for billing" option:

This option works well and does not allow us to make the invoice when SO Item is blocked for billing. But now our wish is to use different variants in case of different reasons why billing is not allowed for this particular line. For example, we would like to use "Answer fr customer" if we still have some misunderstandings or just uncleared questions regarding invoicing:

So basically the idea is to use different variants in case of specific reasons why the billing is not allowed just for quick understanding of the reason and further actions.

We have tried some of those variants which are available in the list, but only "Blocked for billing" really blocks the billing process in VF01. I wanted to ask, is it something that we could change (adjust) in our SAP by ourselves? I just can't understand why other variants does not block the billing process in VF01 if they are also in the "Billing block" menu list as well as "Blocked for billing" variant. In my understanding all of those variants should work in the same way and block the billing process. Or I'm totally wrong? (:

Perhaps someone knows how to fix this issue?

Many thanks in advance guys,

Kim
/// Product Version: SAP NetWeaver 7.5 / SAP Basis 750