Are you using a Respironics machine or a ResMed machine?
You mention ResMed but your profile shows Respironics.
If you are using a Respironics machine and only looking at the time over red line % it may look worse than it really is because SleepyHead's default red line is for the ResMed 24 L/min red line and Respironics doesn't use the same red line.
Respironics never tells us an exact "red line" for large leak territory to begin.
Are you seeing many prolonged large leak flags over on the Events graph?
To get a more accurate red line statistic you need to use a number that is more in line with where Respironics red line might be if they gave us one. Maybe around 60 L/min depending on mask and pressure.
You can change the red line number from 24 to 60 or whatever...Preferences/CPAP tab
Or just turn it off by removing the check mark from show the red line statistic and simply follow the Events graph for leak status.
You may not have as big of a problem as you originally thought in terms of leak.