I created a limit with value 5 per hour for my application plan (it's Fuse flights aggregator booster). I was trying to programmatically access the API using my custom key then and was getting valid response 6x times (afterwards I got expected 429 response) instead of just 5x times.

So I think the limit is not set accurately. In fact it's "x+1" (maybe because of starting from 0) instead of "x".

Additionaly the usage API then returns the number of total hits as 5, but in fact there were 6 hits.