So I managed to install TS+ in my project and managed to make the VSCode language server point to it.
And then I was very eager to try to use the Effect.tryCatch function without providing the first argument as a thunk. But it didn't work. So I went into the code to see how the LazyArg<A> interface was defined. And found out the necessary ts+ JSDOC annotation, i.e.
/*** @tsplus type LazyArgument*/
/*** @tsplus type LazyArgument*/
was not present. Which I think explains why it does not work. Must the Effect library with the TS+ JSDoc annotations be imported from another source?