It can be done if you write your code like this:

    function MyThing() {
      return (
        el(A, {value: 123}, [
          el(B, {value: 456, foo: true}, [
            el(C, {awesome: true}),
            el(D, {awful: false})
          ])
        ])
      );
    }

but there's a reason people prefer JSX syntax