Although I have never tried I am not sure how people could attempt to follow more then 125 per day. If you hit that limit it just does not work any more. Even using a bot or some automated system, I would not think that the system would still apply the limit to the follow action.
On the other hand it would be interesting to know what the limits are on things like highlighting, clapping and responding. These I think are more likely open to abuse. Especially recently I have had at least three different accounts clap for around a dozen stories in a very short amount of time (under 1 minute) and I know it was this because I just happened to open the notifications at the right time and they all showed 2 minutes ago. These people think they will get engagement back from these sort of actions but I just block those accounts.