Efficient query to find invalid number's in varchar column - oracle

Question

I have already asked almost the same question before:
Finding non-numeric values in varchar column
And I received some great answer's and idea's to make not only fix the issue in my query but also make it much more efficient.
Old Query:
Select * From Table_Name
Where
(NOT REGEXP_LIKE(COLUMN_NAME, '^-?[0-9.]+$')
OR
LENGTH(Function_To_Fetch_Left_Component(COLUMN_NAME)) > (Precision-Scale)
OR
LENGTH(Column_Name) - LENGTH(REPLACE(Column_Name,'.','')) > 1)
New Query:
Select * From Table_Name
WHERE (Translate(column_name,'x0123456789-.','x') is not null
OR column_name = '.'
OR column_name = '-'
OR column_name = '-.'
OR Instr(column_name,'-') > 1
OR column_name like '%-%-%'
OR column_name like '%.%.%'
OR Instr(column_name||'.','.')-1 > (precision-scale) ) ;
Known limitations which are okay:
1.) Doesn't handle scientific notation. Its by design as I want to reject those.
2.) Doesn't check total precision (decimal component) however as while inserting oracle itself round's it off I am fine with it.
3.) Doesn't check for leading zero's.
Please help to see if the above query cover's everything and I haven't missing anything.
Another great solution by one Stackoverflow member however increased execution time by 2.5 times:
Function:
CREATE OR REPLACE function temp_is_number(p_test_value varchar2,
p_scale NUMBER,
p_precision NUMBER) return varchar2 is
l_result varchar2(1);
begin
execute immediate 'DECLARE l_number NUMBER; ' ||
'l_test_number NUMBER(' || p_precision || ',' || p_scale || '); ' ||
'BEGIN ' ||
' l_number := cast(:b1 as number); ' ||
' l_test_number := cast(:b1 as number); ' ||
' IF (l_number = l_test_number) THEN ' ||
' :b2 := ''Y''; ' ||
' ELSE ' ||
' :b2 := ''N''; ' ||
' END IF; ' ||
'EXCEPTION ' ||
' WHEN OTHERS THEN ' ||
' :b2 := ''N''; ' ||
'END;'
using in p_test_value, out l_result;
return l_result;
end;
/
Select Count(1) from Table_Name Where temp_is_number (Column_Name,scale,precision) = 'N';