@abstrkx has the wisdom here. “OP-1 Speakers” is automatically enabled and at the top of the Windows 10 audio settings page, but “OP-1 Synth” is automatically disabled and hidden at the very bottom of the settings page. Once that was manually enabled “OP-1 Synth” now shows up in Ableton as an option under MME/DirectX. Recording to and from the OP-1 with Ableton is much faster and smoother than the ASIO4all option and allows playing audio from the OP-1 headphone jack, computer speakers, computer headphone jack, etc. Thank you!