OK, I used the search function and I came up short.

Does anyone have conclusive answers on the topic of a boat ramp in Falmouth which permits overnight parking, say for 2 nights during the week?

The only place I know you can overnight is in east falmouth off route 28. You can't overnight at Greenpond, or Falmouth Harbor.

Child's River allows overnight parking. The ramp is a bit tight and steep and slippery, but they allow overnight.