This is off the MN DNR website.
The DNR recognizes that some boaters are accustomed to power loading. However, it is preferable that boaters do not race their engines while on the boat ramp. Slightly more than idle speed should be all that is necessary to load and/or unload the boat.
I can load my 2008 X2 all the way to the latch without using any more than idle power. See video.