Does setting the load setting between incandescent and LED make difference?
Definitely, but it might not be a difference you can see. This has to do with “trailing edge“ versus “leading edge“ dimmers.
Trailing edge or “ reverse phase“ dimmers are better at feeding current to LED bulbs and consequently may correct Flickering or buzzing you might get with a leading edge or TRIAC dimmer.
A “universal“ dimmer typically has the ability to be changed from leading edge to trailing edge depending on the type of bulb you want to use with it.
With LED bulbs a 70% dim level might bring them to max brightness and anything after that doesn’t really do anything. Do you know if the Leviton adjusts the green indicator lights on the side to show this is 100% for LED bulbs or if it shows you the true dim level?
Sorry, I just don’t know. Hopefully someone who actually has that device installed will chime in and may be able to help with more details.
To answer my own question - the Leviton DZ6HD does in fact evenly distribute the led dimmer level indicators so 100% is max bright.
And, per Leviton, it is a forward phase dimmer.