But IMO the children are the losers when they have to start shuttling between two homes. One of my children is only 3 years old, and my S6 is autistic. They are both have a history of being horrible sleepers. They need the consistency of a regular bedtime routine and a constant sleep environment. I could see one overnight a week becoming a pleasant routine for them but I think that more than that could become a stressor for them.
This lurker agrees with you 100% and especially given the young ages, the autism. One night max for the young 'uns. Two nights reserved for special occasions (treat). Planned in advance.
Gardener
"My soul, be satisfied with flowers, With fruit, with weeds even; but gather them In the one garden you may call your own." Cyrano deBergerac
