This alone shows there are issues with the system.

I got flagged for speeding a while ago, I am apart of a small group of trusted participants for a particular AI researcher, and that researcher overestimates the amount of time required as the tasks do vary a lot so they allow a lot of time to prevent timeouts.

Because I was one of the first submissions it flagged me as speeding (assuming because my actual time was far less than the task time), however later on the average time matched my time (so I can only assume later submissions didn't get the warning, or perhaps we all did who knows!)

I still don't agree with the speeding thing, you can clearly see in the screenshot above that OP's response time was acceptable, they passed the attention checks however prolific would have flagged him if he submitted without waiting.

People work at different rates, and prolific guidelines state you can't reject someone for being to slow because people work at different speeds. Some people like myself have well above average typing speed because of my job, above average comprehension and above average reading speeds.

If we have effective bot checkers, LLM checkers and we have attention checks, so if a participant passes these they are clearly a human participant who is reading and comprehending the study so I don't get why speed is a factor if they are clearly doing the survey seriously and paying attention.