Analyzing string or binary data would be truncated error

Based on the ideas in this post, I've made an improved and dynamic version to help in determining the violating records when inserting into a table:
http://sqlblogcasts.com/blogs/danny/archive/2008/01/12/scuffling-with-string-or-binary-data-would-be-truncated.aspx

create procedure cst_checktruncatederror  as
begin
set nocount on
declare @src nvarchar(max) = 'sourcetable'
declare @tgt nvarchar(max) = 'targettable'
declare @cols nvarchar(max)
declare @sql nvarchar(max)

-- create temporary empty version of destination table (target proxy)
-- note: use a global temp table, because a normal one goes out-of-scope when the dynamic sql returns
if (object_id('tempdb..##target') is not null) drop table ##target
set @sql = concat('SELECT * INTO ##target FROM ',@tgt,' where 1=0')
print @sql
exec sp_executesql @sql

-- get a comma-separated string with block-quoted columnnames that are comparable
set ansi_padding on
set @sql = concat('
select @colsOUT =
substring
(
(
select concat('',['',column_name,'']'')
from information_schema.columns
where table_name = ''',@tgt,'''
and data_type <> ''geography''
for xml path(''''), type
).value(''.'',''nvarchar(max)'')
,2,100000
)
')
print @sql
exec sp_executesql @sql, N'@colsOUT nvarchar(max) OUTPUT', @colsOUT=@cols OUTPUT
print @cols

-- load source to target proxy
set @sql = concat('
INSERT INTO ##target (',@cols,')
SELECT ',@cols,'
FROM ',@src,'
')
print @sql

SET ANSI_WARNINGS OFF -- truncates fields instead of throwing "string or binary data would be truncated error" error!
-- 1. do not use * to insert, because the column order might be off
-- 2. wrap fieldnames in blockquotes [] because reserved words might have been used, e.g. STATE or UNIQUE
-- 3. exclude data types: geography
-- 4. TO DO: destination columns might be NULLable, while the source is not. That results in a different error
exec sp_executesql @sql
SET ANSI_WARNINGS ON

-- return violating records
set @sql = concat('
SELECT ',@cols,'
FROM ',@src,'
except
SELECT ',@cols,'
FROM ##target
')
print @sql
exec sp_executesql @sql

-- clean up
if (object_id('tempdb..##target') is not null) drop table ##target
end