Does anyone know if there's a report part that counts the number of times a machine has had a log-in event over a period of time? or if there is any work around method to get that count on a report?
You could add a Kaseya Custom Field and then schedule a Powershell that updates it with the result of the below (gives you a count of login for the last day):
(Get-WinEvent -LogName Security -FilterXPath "*[System[EventID=4624 and TimeCreated[timediff(@SystemTime) <= 86400000]]]").Count
Change 86400000 (which is one day) to the value needed.
=(24 hours *1 day *3600 minutes) * 1000 milliseconds
Then build a report over your Custom Field (using report part Audit -> Machine Summary ).