Add in Codeunit "UI Helper Trigger" an event fire after OnAfterGetCurrRecord to set Mandatory Field.

The event will use dictionnary.and record of page

the dictionnary display the field ID or variable Name for the key and the mandatory boolean to setup.

[BusinessEvent(false)]

local procedure SetMandatoryField(rec record @recordOfPage,xrec record @recordOfPage,var MandatoryDictionnary : Dictionary of [ Text, Boolean ])

begin

end;

You could evaluate the key of dictionnary with integer variable and if the test pass you can be sure the field of control is mapped with field of record.

to set Mandatory Field, we set the dictionnary value