I'm late to this thread, but I'm enjoying the course!
I'm still on Chapter 3 :) -- but supplementing my reading with David Spivak's papers, and their AQL IDE which they have kindly made available for download.
Personally I have gained from the exercises, esp the easier/counting ones since I'm not used to thinking about categories in this way... (I'm normally working in a situation where the compiler does it all for me, if at-all!).
With regard to following the book: it's very helpful that they chose a simplified presentation for their material, since we're not all category theory experts. But your lectures are a better road map to better understanding the necessary category theory than say following the references, which being honest I often don't do.
So, thanks! I'm grateful (and impressed, as always) for the energy you've put into this, and I'm sure you'll find a graceful way to wrap up (somehow!)