There are two different types of export, named and default.
You can have multiple named exports per module but only one default export.
For a named export you can try something like:
// ./file1.ts
const arr = [1,2,3];
export { arr };
Then to import you could use the original statement:
// ./file2.ts
import { arr } from "./file1";
console.log(arr.length); // 3
This will get around the need for arr.arr you mentioned.
How do pirates know that they are pirates?
They think, therefore they ARR!!