As I recall (but since I retired practically everything about pensions has vanished from the mind, thank goodness, so I may be fuzzy on this), if everyone is in their own group the IRS considers that as 'by name'. Therefore, to pass coverage you can only use the ratio % test. While that shouldn't be a problem, keep it in mind.
At first thought, it seemed off. But, you are talking about such a short loss period that an extra day is a significant increase. If it is 4 days late and you add 1 more day, its a 25% increase. If it is 104 days late and you add 1 day, it is less than 1% increase.
The math:
4/30 is $2.13
5/1 is $4.27
5/2 is $6.40
5/3 is $8.53
5/4 is $10.66
5/5 is $12.80
5/7 is $17.06
5/15 is $34.10
Counting 4/29 as a day in the loss period:
Amount doubles from 2 days to 3 days (2.13 to 4.27) +1 day
Amount doubles from 3 days to 5 days (4.27 to 8.53) +2 days
Amount doubles from 5 days to 9 days (8.53 to 17.06) +4 days
Amount doubles from 9 days to 17 days (17.06 to 34.10) +8 days
The amount due doubles as the number of days late you add to the prior number of days doubles.