Different Read Only logic of Tabs in some cases

I find out that there are two different behaviours of read only mode on tabs.

Let's examine that you decided that readOnly logic of Lead window should depends on Lead Status field. When this field has value Converted then whole tab should be non-editable. So I change readOnly logic of this tab to @LeadStatus@=C. (Also set LeadStatus as always updatable)

Use Case A:
When field LeadStatus doesn't have any dependent fields and callouts, then save of record is needed to change readOnly mode of tab.

Use Case B:
When field LeadStatus has some dependent fields or callouts, then changing of Lead Status value will results into changing readOnly mode of tab immediately.

Steps to reproduce:
Open Window Lead -> tab Lead and changed ReadOnlyLogic to @LeadStatus@=C

Use Case A:
Lead Status shouldn't have any dependent fields or callouts in current configuration.
Use Case B:
Go to Table and Column AD_User and change callout of column LeadStatus for example to org.compiere.model.CalloutOpportunity.salesStage (it's not important which callout will be filled).

I would expect if iDempiere should always support Use Case B rather than A.