Can I use an elbow on a tub overflow to clear framing?

I’m installing an alcove tub (Kohler Underscore), and a beam runs under the center of where the specs show the overflow connection to the waste line. The area under tub drain itself is clear.

Is there any reason why I can’t use an elbow where the overflow comes down, install the drain tee in the horizontal section from tub drain, and connect to the waste line there?