It's documented on that page:
Note that files are written back to the remote only when they are closed and if they haven't been accessed for --vfs-write-back second. If rclone is quit or dies with files that haven't been uploaded, these will be uploaded next time rclone is run with the same flags.
--attr-timeout duration Time for which file/directory attributes are cached. (default 1s)
That's how long it keeps file attributes in memory when it gets a listing of them, which is normally 1 second.
Best bet is to use defaults and if you want to change something, understand what the flag does and why you are changing it.
I can't figure out what you are really trying to get to so I wish I could be more helpful as you seem to have a random stream of questions that are all unrelated.