It would be good to be able to reset statistics so if you have problems setting up the alert (i.e. it fails a few times until you get it right) then you will never see 100% uptime, but you should.
You can simply remove and add your check back once you’ve find the right settings, that’ll clear the history ;)
Of course if this is a business critical need for you, you can simply ask the support and I'll erase it, but there won't be a button for that.
We're talking about setup here, you shouldn't have your custom status page already setup and if you do you can change it. It should not be easy to erase your downtime history, especially if you have a public status page
Sorin Ionuț Sbârnea commented
Not really a good alternative as it would require you to reconfigure your DNS entries due to token regeneration.