The adaptation of the scrutiny rites for child catechumens is confusing (RCIA 291). Instead of clearly labeling the rites as scrutinies, they are called “Penitential Rites (Scutinies).” And even though the title is plural, only one text is given with an instruction to write your own for a second, using the given text as a model. Nothing is said about a third scrutiny.
There are nine readings listed as options for the liturgy of the word and, although the traditional Johannine gospels are listed among them, there is no requirement that they be used and no emphasis in the rite on the progressive nature of these three traditional scrutiny gospels.
Most parishes that have child catechumens simply include the children in the regular scrutinies with the adults. If the liturgy is celebrated well, it is as meaningful for the children as it is for the adults.