I think Scott's first video says it well enough near the end... there is no separate converter needed on that ACERT era. None is seen on my original system. You just need to convince your air quality department of what they should already be aware of.
Revisiting my previous note, in 2016 I got confirmation from our Oregon DEQ dept. that our coach met their heavy duty diesel (over 8500lb GVWR) guideline, and I completed a Declaration of Exemption form. A Certificate of Compliance was issued, as is normally done with each 2 year test of most vehicles, but this one was put on permanent file. Reregistering every 2 years now requires DMV to only reference that file to verify air quality regulation compliance, and the coach does not need to actually be tested. Don, you should inquire whether Colorado may have similar procedures. My contact that expedited things was with DEQ, not DMV; as I did, you may need to find the right person willing to assist.
-Joel
I include a better angle on my muffler and pipes, although still not perfect. Yours should look much like it however.