Calculating block duration is a lot more complex and time consuming that merely checking the number of ads. Currently, you can click on a block to see its duration so you can e.g. check suspicious blocks with high number of ads.
There's also the Test all blocks button, it checks each block duration, and if it's higher than specified in Settings / Misc, it will show a warning sign in the grid.
Yes, reports received, thank you. How often does it happen? Does it prevent you from working normally with Ads Scheduler?