I'm sure you know that JSON are object literals in TypeScript, there isn't really even a serialization process that's needed there. The AST/IR can still be in JSON, but the authoring surface can be a restricted subset that does not allow logic to execute, that way you can still get the type safety and functionality of TS when you need conditional/loops/logic without throwing away what TS already gives you.

I mean, it would be great if you guys would have like a "TSON" that is basically "JSON with type declaration and comments" from TS, which I think would just solve a lot of problem straight up. JSON itself is just too restrictive and comes with its own bracket verbosity tax.