Applied McGregor's LUT and Ultra Key in Premiere. No garbage matte files and only adjusted levels to bring shadows and highlights within 0-100 IRE range.
Ultra Key used by selecting only one area of the screen to key the maximum area possible, so there are problems, not a totally clean matte in some areas of the composite. Great 10-bit files to work with.
Thank you John Brawley for providing the test green screen footage, and background clouds were sourced from one of John's earlier BMPCC samples.