Ipl, the higher the settings the more effective?

Does using "higher setting" for ipl mean that it will be more effective or is it more finding what settings work best for you? Each ipl I have the dr increases the settings but it seems is though the higher it goes the less effect its having on reducing my redness, Im not sure if this is because I've reached a point where ipl is no longer effective on me or because I need lower setting to see the best results. And also do certain settings decrease redness when flushing and others decrease background redness?

I know this this is a broad/vague question as there are a lot of different aspects to ipl(filter, energy, how many passes...) but any knowledge or experience anybody has about what im rambling about would be really appreciated
Thanks

Ipl, the higher the settings the more effective?