With respect to DAR I totally disagree.

Set your parallax and stick to it. You have 2 main choices at x10.

1/ Blurred at 8, fuzzy at 10 and slightly blurred at 45.
2/ Very blurred at 8 , blurred a 10 and crystal at 45.

It's down to you playing the odds. if you want to Range find by bracketing you need crystal clear at 45, and run the risk of not being able to see a well shot reducer at 8..
On the other hand you can use the optical resolution to rangefind - say clear at 35, bit blurred at 45.. and get good image at 8 to 10.

Your choice but chopping and changing between courses will simply confuse you in a comp.