Whenever I use EOS Webcam Utility (whether it's "pro" or a previous version) and check Activity Monitor (I'm on a 2018 MacBook Pro), it says EWCService_x86_64 is using more than 100% of my CPU. Whether it's with the regular Webcam Utility Pro app, OB...
I haven't used the webcam utility in a little more than a year now so it might have changed, but I remember that I just searched for it using Mac's Spotlight and the program came up. From there, the settings were pretty easy to find.
I've already had that setting applied when the problem became apparent. I've double checked and the problem is still there.I'm using a Canon 80D if that information helps.