RV defaults to a weird sum in center channel mixup when playing stereo content in a 5/7.1 playback environment

RV appears to be doing some weird mix-up to create an improperly mixed center channel when you play back stereo content in a theatre with 5.1 or 7.1 set in presentation mode. This happens both in BlackMagic and through Windows Audio.

While the manual explictly says the following, it seems like this is a very rarely desired behavior: Similarly, playing back stereo media to a 5.1 device will see the media's stereo FL and FR content mixed up to the 5.1 device's FL, FR and FC only.

As I’m informed, this likely relates to some of the early days of some multi-channel formats where doing a mixup was expected.

Can we please get this behavior disabled or at least disable-able? Even with the mixup that exists as-is, this is broken as it is not summing properly and creating clipped audio.