Just a thought, but don't apple have a pretty good helpline for their hardware and OS? I know that the son of a family friend works at one here in the UK, he is very knowledgeable, and willing to do research for answers he doesn't have in his head!
Worth a go?
7DII+Grip, 7D+Grip, 40D+Grip, 5D+Grip, EF 24-105 f4L EF-S 17-85, EF-S 10-22, EF 70-200 f2.8 L IS II, EF 2x III, EF 100-400 f/4.5-5.6l IS II, Σ17-70 f2.8-4 C, EF 50mm f1.8, 550EX, Triopo TR-985, Filters Remotes Macro tubes Tripod heads etc!
5D, 20D, 24-105, BG-E4, BG-E2N, 17-85, Nifty 50 pre owned.