Yes, that's what I mean. If you return JSON you force a DMR-based client to parse the JSON.

Side note: the messaging subsystem has some ops that return JSON strings instead ModelNode. But that's

1) Because the subsystem was trying to provide the same stuff the existing HQ management API did, in case users (e.g. coming from AS 6 / EAP 5) were counting on it. HQ provided JSON.
2) and/or I was just too busy to convert the already existing JSON output from HQ into ModelNodes and expose a separate op that returned ModelNode. Although IIRC I tried to do at least some of that.