Can I change my Deadeye level?

While progressing through the game, I've unlocked 3 levels of Deadeye:

• Free targeting mode, where time essentially slows until I take a shot.
• Auto-mark mode, where time slows and any target I land on with my crosshairs gets a bullet
• Manual-mark mode, where I get to press a button to mark targets by pressing the right bumper

Sometimes I'd really like to be able to use the "auto-mark" mode when I've got a bunch of targets, or targets hiding in brush. Most of the time, though, the manual mark mode is better for me.

Is there any way to (without cheating - achievements ho!) change my deadeye level to one I unlocked previously?

There is no way to change your Dead-eye level without cheating.

There are 7 cheats you can get for being a Social Club member, 2 of them will allow you to change between Dead-eye level 2 and level 3.

Doing this will disable saving and achievements/trophies.

Level three gives you the extended time of level two, but with more control. I found myself consistently hitting unintended targets (I keep shooting the man instead of the rope in he stranger quest to have the man from being hung) with level two. Switching in and out of Dead-eye mode to retarget gets bothersome.