Very unlikely to encounter an issur kares even in a poorly run program. Kezayis b’kdei achilas peras is not going to happen. I was referring to a program that has decent kashrus standards. My point was that the atmosphere can be uplifting for some but unacceptable for others depending on where they are holding spiritually.
Key to deciding to go to a program is directly related to the purpose of going.
If the intent is a better experience for your family and to alleviate the 6 week preparation process at home (i.e. too hard to juggle for the parents together with their jobs/newborns/schedules, etc....) , and instead join a program, enjoy, be inspired, uplift others, inspire our own family and the people around us, then it doesn't matter as much what the people around us are doing. And like Rabbi Jacobson says, "
Royalty does not notice what others are wearing."
We aren't going as if we are attending an amusement park => to see what we can enjoy the most, and eat the most.
We would be going to have a Pesach that makes us better people. And to make a better year and future for family and memories.
If we and our family are strong in our beliefs, and our children are not swayed, too vulnerable, or affected by peer pressure, then the pros (if we can afford it) outweigh the cons.