I removed limit decoding from all cameras and plan to keep it off. It was on only for cameras that used only ONVIF triggers and not BI's motion detection, only ONVIF triggers. The only difference I see is the quiescent load in BI went from around 3-5% up to 7-10%. Small enough not to matter and pretty much what I would expect - slightly more decoding producing more CPU usage. Not seeing any noticeable difference when cars drive by or people walk by.Most of your initial problem of maxing out on motion was related to the use of limit decoding, you should not be using that option.
make sure that onvif is setup correctly in the cam and BI and that you are using the onvif login
Is this what I should expect? If not, what difference should I expect and why? I am going to leave limit decoding off - you have much more experience with BI than I do so that seems safest. If it matters, I am running BI as a service and viewing via a second instance of BI on the same PC run as an administrator. No external viewing ever.
I believe I have all cameras setup with just a single admin account and no separate ONVIF account. I will double check in a few days.