It would be nice, but it's a major project - it would involve running the TypeScript compiler and language service in the editor. It'd probably involve upgrading the script editor as well. If I could snap my fingers and it was done, I'd definitely do it, but things are usually not that easy! In the mean time using an external editor like VS Code is a pragmatic approach that should still work pretty well. You could also file a suggestion for this as if it collected a lot of votes we'd be more likely to prioritize it.