[dm-crypt] Cryptsetup FAQ is confusing re: key-file length and newlines

The FAQ as of today (2020/7/15) states

Make sureno trailing newline (0x0a) is contained in the input key file, or thepassphrase will not work because the whole file is used as input.

But then a few lines later it suggests

head -c 256 /dev/random > keyfile

Obviously if /dev/random is used, it's possible that the keyfile will end with a trailing newline.
I think you're trying to distinguish between 
   
   - A file which contains a human-readable passphrase which could also be entered interactively, and    

   - A file which contains random bytes.     

In order for a passphrase to be entered interactively, the passphrase must not end with a newline.  Therefore, when intending to use both a keyfile containing a passphrase and also enter that same passphrase interactively, the keyfile should not contain a newline (anywhere), including a trailing newline.  If a keyfile does contain a newline (anywhere), the text of that keyfile will not be able to be entered interactively as a passphrase.
Additionally, I see lots of guidance on the length of a keyfile which uses magic numbers, both on the internet and also in the FAQ.  Examples are the value 256 above, and the parameters bs=512 count=8 for dd.  If I understand the FAQ correctly, the actual advice is


Plain dm-crypt: Use > 80 bit.  ...  If paranoid, add at least 20 bit.



This implies (taking the worst case) that 


head -c 13 /dev/random


should be sufficient (13 * 8 bytes = 104 bits > 81+20 bits), and 256 bytes is "overkill".  I do understand that some reasonable amount of overkill is essentially "free" and therefore can be used "just in case".

Did I understand these two concepts correctly, and if so, could you clarify the FAQ?
Thanks!-- John Wiersba