You can set default properties by having at least once instance of the sprite places in the layout editor, even if the layout is not used otherwise.
I did have one instance in the layout but new instances created did not keep those same default properties.
I figured out a workaround where I can put multiple instances in the layout, one for each container I will need, and they keep the default property. I assume that is because the container uses the existing ones, not creating new ones.
Not ideal if I want to, for example, dynamically create/spawn enemies using line of sight. For this current situation, I only need a set amount so can continue with this workaround, for now.
Good note that I can use a different layout, even if not used. I will test that as well.