Can you say precisely what understanding is sufficient at what level at what age?
I think the answer again is no.
I don't think we will ever agree on Baptism, but I'm wondering about one aspect: in your view does Baptism matter, benefit, make any difference?
All other things being equal, is there any significance whether one is baptized or not?
Mark 16:15-16
15 He said to them, Go into all the world and preach the gospel to all creation. 16 Whoever believes and is baptized will be saved, but whoever does not believe will be condemned.