Nice script. Three(minor) comments:

First, ** While running the below query if you find any query which ** is repeated in the comment header.

Second, I don't understand why you have WHEN [spn].[open_tran] = 2 THEN, couldn't you remove that and change

WHEN [spn].[open_tran] >= 3 THEN

to

WHEN [spn].[open_tran] >= 2 THEN?

Third, the case below will never happen

CASE WHEN [spn].[open_tran] = 0

because of the filter in the WHERE clause:

AND [spn].[open_tran] <> 0;

thanks