The edit api should be able to handle watching of pages, and also to distinguish between per default watching and per edit specified watching. Following cases should be possible I think:
Case | Page | Default | Per Edit | Result
1 | null | true | null | true
2 | null | false | null | false
3 | null | true/false | true | true
4 | null | true/false | false | false
5 | true | true/false | null | true
6 | false | true/false | null | false
7 | true/false | true/false | true | true
8 | true/false | true/false | false | false
Where null is absent page or parameter not defined, true is either watched page, or watched specified, false otherwise.
Version: unspecified
Severity: enhancement