Thanks for the footage and thoughts, Nigel. Looks great! The colors do look more saturated in Canon log than S-log, which looks really flat.
According to Canon, view assist isn't available in HDMI or HD-SDI because they didn't want people to accidentally think they were recording log gamma (link). Maybe Canon will change this in a firmware update if there's enough demand. But there might be a potential workaround in the future: Canon plans to release the specs to the EXT 1 and EXT 2 connectors, which has the video feed to the LCD monitor. So in theory a third party could tap into EXT 1 and EXT 2 with a breakout box that gains access to the LCD/VF video feed with view assist.
According to Canon, view assist isn't available in HDMI or HD-SDI because they didn't want people to accidentally think they were recording log gamma (link). Maybe Canon will change this in a firmware update if there's enough demand. But there might be a potential workaround in the future: Canon plans to release the specs to the EXT 1 and EXT 2 connectors, which has the video feed to the LCD monitor. So in theory a third party could tap into EXT 1 and EXT 2 with a breakout box that gains access to the LCD/VF video feed with view assist.