You can sign it now at Change.org . And also sign this petition from Philip Bloom where he asks Sony to make an MI shoe OLED EVF.

CineD explains why LUT support is so important:

If you own or use an FX 30 , FX 3 , FX 6 , etc., then you can already load custom LUTs. Even some other Sony cameras offer this menu function, such as the vlogging ZV-E1 camera and the newish a7cII . Neither of the latter would be considered “Cinema” cameras by anyone. So it’s a little surprising that they would offer this functionality in some of their cameras, but not others – especially their flagship lowlight camera, the aS7III , which is used most by filmmakers.