For years I have posted numerous times on DCP about DCI and smaller corps benefiting by going to a regional model.
Divide it by regions, West, South, etc. (5 Regions). **See Below**
Start the tour on 2nd week of June through the end of June.. At the end of the regional tour, have a regional championship, with the regional winners getting a spot in the top 5. But this will require all corps in the region to only compete within their region. One exception, every 4 years a corps , one corps may compete at another region, as long another corps from the recipient region sends a corps to that region for the sake of competitive balance. For example, if the Cavaliers visit the west region, then the west region corps will need to compete in the midwest region, whether it's BD, SCV, etc. Same goes with the open class which is already the case. Then a short week break for July 4th parades, travel to start the national tour etc.
National tour could start the week after the 4th of July Break.
Here are the numbers, please feel to correct me here as I did this off the top of my head:
West - 5 World Class Corps, 8 Open Class and 1 Soundsport = 14 - DCI West or DCI Pacific
Northwest - 4 WC, 4 OC, and 2 SS = 10 - DCI Northwest
South - 5 WC, 4 OC, and 5 SS = 14 - DCI South
Midwest - 6 WC, 4 OC, and 5 SS = 15 - DCM (Drum Corps Midwest)
East - 3 WC, 6 OC and 5 SS = 14 - DCI East
As you can see, there are enough units to field shows per region. Also gives the OC corps the option to give their members opportunity to compete in the regional tour only which is a win financially, plus giving the ample performance/competing opportunities.