I don't like it but it fits the Racin' with DO theme of changing things at races.
If it is only 5 minutes that's ok.

I think throw the yellow flag for 5 laps, laps count.
That way it slows the race, laps count. But cars that stop are still on the same lap as the lead cars, just on the tail of the field as they come out of the pits.
Give the fans a break to piss, stretch, get a beer and talk with your fellow fans your with.

Start them double file, everybody on lead lap.
Cars that don't pit are leading the race with their race set up for 100 laps.
Cars that pit change tires, fix the front end, add fuel, give the driver a rest. Starting on the tail ready to race! Fuel only? 1 tire ? Two tires? Adds to the event.

Give the fans free popcorn at the break.
Will cost most teams another set of tires, true but they could of stayed out as well.

SO I don't like the tradition being jacked with BUT !
If Sergeant doesn't make money with this race he is probably done with the Hoosier 100. Mods on miles normally make a lot of money?
Not many promoters standing in line to take it over .

So Yellow flag between lap 50. Laps count in race length, Lapped cars get laps back too.
Teams can chose to pit and race 45 laps from the rear or let their driver adjust the dri-bar and race a 100 laps.

Only way I can see the red flag at 51 is a time frame of 5-10 minutes. Sharp!

Every driver&team are properly lined up and knows where to be on the next lap around. No extra laps to line up the field.
Yellow flag 5 laps @ 50 , What options do teams have?
1 - Fix your that got crashed.
2 - If your driver is a newbie to the miles, gives him a break and you can talk with him and adjust for him.
3 - Teams can use a light load save tires and take on fuel only !
4 - Teams can add fuel, tires & adjust the car, takes longer, starts deeper in pack.
Cost of Tires extra.
5 - Teams can load up on fuel, set it up for 100 miles and race!
Remember May 10th Bob Sargent will be on the show at Kelly's.
Stop by or send me questions and ideas and we will address them Monday. 7 PM est
www.RacinwithdoShow.com
Hope to see you at the show.
D.O.