If you use the BI Fusion smartapp to link SmartThings and Blue Iris, then your cameras become motion sensors inside SmartThings. Then you can use it just like any other motion sensor and turn a switch on/off or anything. I prefer the Super Notifier Smartapp for those things. It’ll let you turn switches on or off based on all kinds of things and has a whole bunch of execution restrictions too so you should be able to do whatever you want. The BI Fusion instructions are a bit out of date, but still work. (Blue Iris 5 changes a lot of the look of things). Check out each of their forums, should’ve answered any question you may have there, but if just post in there.