@ClockworkOcean I actually did that in my video, I just used 1x master (parent) Material, with no Instances whatsoever and as you can see, I was able to individually set the Color, Specularity and Roughness to both objects. That clearly shows you can modify the same Material with different parameters, at the same time, for multiple objects, without the need of instances.
@Arkiras The fact that I’m using only 1x master (parent) Material actually still grants me the same workflow benefit 
But I know what you’re saying, so ok, let’s say that Material Instances do have some use as far as workflow goes, especially for artists, masking away the implementation and only exposing the needed parameters. BUT the whole Constant vs. Dynamic thing is still a huge mystery, as the MID overhead is quite big and at the time of writing this, we both see it makes no difference in either UE4 or UE5, as you can do the same thing with MICs directly, without converting them to MIDs.