Is Blender capable of additive animation blending or not?

For example, to layer spine animation (breathing, turning around, etc) over another, fullbody animation? Trying to figure out NLA by myself gives me existential crisis. I need to know for sure if it is possible or not

Here is a video that might be helpful

It’s inside NLA’s N-panel:
nla_add

Don’t know for 2.8 but in 2.7x it was broken without add-on