Maybe I misunderstood, but I thought the person I was responding to was suggesting having the option for sound typing enforced in typescript, at compile time. Because if it's at run-time... well the run-time is Javascript, so there's of course no typing there. This isn't really on Typescript

There are however javascript libraries which allow you specify object schemas and throw errors when mismatches occur. Perhaps the suggestion then is to build some shared layer between the TS compiler and V8 so that similar schemas can be autogenerated by the TS compiler and enforced at run-time.

There is generally no typing in run time. One of the practices in writing compilers is to skip type checks during run time, because you know beforehand that no type errors are possible. That is type erasure.

If you're interested, lookup existential types. Very interesting stuff.