Alerts and emailing

[customer idea]

At the moment, there is available email alert only by "fixed" First Pass Yield limit – if value is same or lower than FPY limit setting.

Instead of alarming on a given threshold (e.g. below 95%), how about to monitor the change/drop in percent points instead?
Meaning that if FPY value from day x is 90% but drops to 85% (5% points) on day x+1 alert will be sent?