I installed that utility, Recording Indicator Utility, and it works - the dot goes. However, installing, turning it off and turning it back on, whilst simple enough, is cumbersome and requires a couple of restarts for each step. Here are some notes to help you decide if it is right for you.
When you run the software for the first time it guides you through the installation steps to turn off System Integrity Protection, which requires you to restart in recovery mode, go to Terminal and run a command to turn it off. When you restart, you go back to the Utility, click the toggle to turn off the indicator, enter your admin password, restart again, and then it is gone. I tested that on a couple of different monitors: no dot and that does feel better, I couldn’t stop looking at it.
I followed the process to restore the System Integrity Protection (SIP) to its default which goes like this: click the toggle in the utility to re-activate the dot, then it asks you to re-start. When you go back to the utility there is a new button to click to ‘raise security levels’ - click that, enter admin password, re-start again and you are back to normal. I should add that the last re-start took a while, probably no more than 5 seconds before the screen went ‘off’ then a little longer than usual to reboot. I guess it is doing something …
I guess there are 2 risks. One is that while SIP is disabled your machine suffers from an attack that SIP would have prevented. The second is that the Utility does not work as described when it restores the defaults and leaves you vulnerable when you think otherwise.
If I understand the Apple article correctly, SIP protects your machine by preventing software installers from modifying system files. Unless there was malicious code lying dormant from a previous installation, a machine with SIP de-activated wouldn’t lose the protection of SIP until software was being installed. When software is being installed without SIP the installer has root access to the whole file system; this was stopped by introducing SIP in OS X El Capitan, in 2015. So, it is a level of protection we have had for getting on for 10 years.
Despite restoring defaults using the utility, I’ve not been able to test that SIP is correctly running. I guess I will have to trust the developer on that.
If I understand correctly, with SIP off, any time you are required to give your admin password in an installation you are potentially at risk. So, if you are inclined to install software on a whim, perhaps its not a good idea. Perhaps if you had a machine or a partition solely for performance work, with no access to the internet for example then you could leave SIP off once you have installed what you need.
Here’s the link
On balance, I think the option to overscan on your projector is probably easier!