I have a Question regarding using the IoT Network in my setup.

I am controling my home with Apple Homepod Mini's and they are setup on my 5 GHz Network as well as my phones and Apple TV.

If I use the seperate IoT Network on 2.4 GHz on my Deco for all my Smart Home Devices (Locks, Camera's, Switches and Lights) will this still allow my devices to all work properly together.  

Will devices that can usually work even if Internet is down still be functional when using locally still function?