Nemeth formats tells us NOT to use the number sign if there are only numbers including decimals and commas. Otherwise use the number sign. If the dot 5 is used to fill in the spaces between columns, does the table then require the use of the number sign?
That is correct. The dot 5 is not a numeric symbol so the numeric indicator would be required if guide dots are used, or if dot 5s are used to indicate a column with no data.