Override audio mixer output channel count

Is this doable in any reasonable way?

From what i see in the code, FMixerDevice::GetDeviceOutputChannels just returns value from PlatformInfo.NumChannels which according to answer here just listens to IMMNotificationClient.

I would like to implement a manual override of this setting to enable edge-case users, such as software audio downmixers (like built in Windows 10 spatial sound API with Dolby Atmos for Headphones/DTS :X/ Windows Sonic and such), which rely on being fed multichannel audio from the get-go but as far as windows device configuration goes, they report as stereo devices.

My question is, whether it’s doable without rebuilding entire engine?