Your messages shouldn’t just be dropped if you’re sending more than once per second (although over a period of time that will exceed the lowest rate limit for non-mods/broadcasters). If you were to break the rate limit you would receive a short ban and not be able to send anything. What is possible is that if you try to send messages too frequently there may be anti-spam measures that prevent some messages, and the exact nature of what anti-spam measures Twitch have in place isn’t disclosed.
As for the rate limit as a moderator, that is documented where you linked.
100 per 30 seconds Users sending commands or messages to channels in which they are the broadcaster or have Moderator status
Keep in mind though that the limit is global, so you could send 21 messages in 30 seconds in a channel where you’re a moderator without issue, but a single message in a channel you’re not a mod would put you at 22 messages which is beyond the rate limit for normal users so would result in a temporary ban.