Had a Dell perc h310 I wanted to use for a Truenas install. Absolutely stellar writeup that gave me enough confidence to cross flash the dell card instead of ordering a different model already LSI branded. Worked perfectly by following this guide.
Interesting and very useful; however, I would recommend removing Desktop and Laptop drives since it is not recommended using them with Free/True NAS. Also, I'm surprised to not see any SSD or NVM. At the end it might worth it to make this collective such as using a Google Drive, so we could help you to maintain it.
Perhaps adding ARC is similar to, but not the same as OS level file system cache. And explain the difference in straight forward wording.
Plus, after the ARC section, perhaps adding a L2ARC paragraph.
Then add a section on Special Metadata vDevs.
Last mention De-duplication. My suggestion here would be to state if you don't know how to design and implement, so that you have to ask beginner questions, then you should NOT be using De-duplication.
I am not saying these new sections should be all encompassing, but adding the general description and pointers to more detailed information, I would think would be help full.