Agile Sprints vs. Design Sprints
Jay Melone

I could not more enthusiastically endorse your claim that bundling Design and Agile sprints into one is best for small size features and not large projects. Often the Design activities are called Sprint 0 (see

If you try to design a large new product and build it at exactly the same time, there is going to be a lot of re-work: Ready, Fire, Aim.