qe.project.getActiveSequence().player.setLoopPlayback does nothing

I know I know, QE is not supported. This could have been a project refresh issue but when I click around and focus I still don't see the loop playback enabled.

When I use qe.project.getActiveSequence().player.play() it stops at the outpoint or otherwise doesn't even start if the player position is outside of the in-out points. If it's inside, it does play along but without any looping.
Is there a way to programmatically (CEP) enable loop playback and then start playback?

If not, is it possible through the CPP SDK?