You can detect code points that conflict with ASCII semantics either before or after migrating to Teradata LATIN. Corrective action can then be taken under either environment.
SELECT cchar FROM tab1 WHERE INDEX(cchar, '80'XC) <> 0 OR INDEX(cchar, '81'XC) <> 0 OR INDEX(cchar, '82'XC) <> 0 . /* all codes 83-FE */ . OR INDEX(cchar, 'FF'XC) <> 0;