Bombed for towing or lightly bombed?

What percentage of these tuners are actually smog legal. I have heard a lot of them are sold with the stipulation they are not for on road use. California now requires a smog test on diesel vehicles, one ton and below, because of the misuse of tuners. But these tuners can be removed prior to the test. Doesn't make much sense does it.

Banks was the first manufacturer that I knew of. That offered many smog legal tuners. Not sure if that is still true.