Appreciate the few people that actually replied with an answer to this question.
Solved this issue when using an old 5Dmark iii as a webcam years later from this post.
All these other "duplicate" questions don't mention 5Dmark iii so they never appeared in a google search, so thank you for the people that actually took two seconds to answer the question rather than just belittle the person in need of help.
This was super helpful for this webcam use-case.
External HDMI recorder:
Enable the Clear Overlays feature to hide the focus box and the 16:9 bars.
Make the half-shutter button sticky (Prefs menu) to prevent the camera from turning off LiveView after 30 minutes.
Solved this issue when using an old 5Dmark iii as a webcam years later from this post.
All these other "duplicate" questions don't mention 5Dmark iii so they never appeared in a google search, so thank you for the people that actually took two seconds to answer the question rather than just belittle the person in need of help.
This was super helpful for this webcam use-case.
External HDMI recorder:
Enable the Clear Overlays feature to hide the focus box and the 16:9 bars.
Make the half-shutter button sticky (Prefs menu) to prevent the camera from turning off LiveView after 30 minutes.