Hi Shehal,
Historically, SD1029 check was introduced to be applicable to all character variables as you suggested.
However, there are many valid cases when collected data utilizes special ASCII or Unicode characters specific to non-English languages. Therefore, the original business rule was limit to variables which values may be used as Names and Labels of new variables during transpose process. For example, if you like to convert LB data from vertical to horizontal structure, then you can use values of LBTESTCD as Name and LBTEST as Label of new variables which store LBSTRESN values.
Kind Regards,
Sergiy