Your espresso recipe and supporting info is excellent. I've learned a lot from it.
If you were to include temp in your recipe, how would you do this?
In the past I have just left my machine set at 96C. Setting temps wasn't convenient and its brew boiler was big so it took a long time for a change to stabilize.
My new Linea Mini is on the way and it has a simple way to adjust temps and its small brew boiler stabilizes very quickly so I'm planning to add temp as part of my brew recipe.
I've noticed that you don't mention temperature as a recipe factor. Likely part of the reason is that while many machines now have a digital temp control, brew temp changes still take a long time to stabilize so it is still somewhat inconvenient to use brew temp as a recipe factor.
I know that 96C/205F is the typical brew temp used for most coffees. From what I've read, +- 2C is the typical temp range normally used and that this has a small impact on TDS; however, I've also read that it has a bigger impact on taste. I'm guessing that this is due to its impact on extraction balance.