Here are some examples from my side
1. src/start.ts is only mentioned in the global middleware page. This makes you confused what the file is and if it should be included all the time due to its name
2. In the server functions page, there's no links to getRequest, getRequestHeader, etc. Even though it says you can get more info here
3. Code splitting is documented in TS Router, but not in TS start in terms of how to pass config in vite.config.ts. I had to assume there was a "router" property on "tanstackStart()"
4. Env variables runtime validation section I believe is incorrect. I tried that code and it lead to zod errors when importing any env, due to the other env also being there. I might have done something else wrong though and I fixed it with T3 env. Maybe worth mentioning T3 env?
5. I haven't seen in the docs to not use a server fn withing another one. I am still not 100% sure this is not allowed, but it doesn't seem to work for me
6. This is for TS router but still applies. In the Tanstack Query integration page, at the bottom it says redirects are auto-handled unless otherwise configured. I haven't been able to get this to work reliably and there's no examples or anything else to go on
Overall, the docs lack depth. They are just direct to the point, e.g. "This is X, you can use it for Y". It lacks a lot of the time "Here's how" and "If you use Z, then also add this" and a link to more info
This makes anyone using it have a bunch of question marks, and it makes it very difficult to have confidence that you're using TS Start the right way