@Village Guy I guess i'll go back to the original question: I am using, 
I THINK , cloned cameras (Amcrest with 2 streams).  I don't really have space limitations, but seems wildly inefficient to continuously record 16 4k cams.  What I thought I was doing was taking stills from the SD stream, sending them to a folder monitored by AI Tool which would then tell the HD stream to record a clip when a relevant event is observed.  The 1st post in the thread suggests that I should be using flags as of v1.67 as the preferred method, but you're saying it shouldn't really matter and that flags are only useful if you are continuously recording?