Reverting reaction fire

[FrozenWerewolf]

So, I decide to send a rifleman up near the corner of a wall, as he had seen an alien pass by it previously. I turn on reaction fire and am expecting the alien to pop out again, so, theoretically, my rifleman would be approaching the corner with his weapon aimed just past it, ready to fire as soon as he sees something. I end the turn and the alien does indeed walk by. My rifleman does absolutely nothing. The alien proceeds to turn to face him, casually raises his gun, and then shoots my soldier in the face, killing him. Ugh.

I'd rather not have to wait for aliens to appear, walk around in circles, and perform a little dance in front of my soldiers before they can shoot, so I ask: is there a way to revert the reaction fire system back to the original "soldier fires as soon as they see something"? I searched and found something about adding an autoexec.cfg file, but it seemed to be for earlier versions; I went ahead and tried it anyway and found that it didn't work. Didn't find anything in the Gameplay section of the Options menu either.

[TBeholder]

I'd rather not have to wait for aliens to appear, walk around in circles, and perform a little dance in front of my soldiers before they can shoot, so I ask: is there a way to revert the reaction fire system back to the original "soldier fires as soon as they see something"?

It's not problem-free either. Especially if you can't get a soldier to pop back behind the corner without all aliens in sight firing everything they got.
IIMO what RealSpirit proposed and my arthropodean self formulated would be a reasonable trade-off: if you want to cover one passage, the soldier doesn't need to turn and aim much, so you'd get much better timing with just about everything, if you're in the middle of nowhere and expect anything from any direction... yeah, it's not a very good situation.

[anonymissimus]

Use noobs in reaction fire positions. RF just cannot be relied upon (and it seems pretty buggy). Place RF units in the open, there must be nothing covering the line of sight and shooting. If there is a corner or anything, I can assure you, the alien will fire but your soldier will not, even though they are using the exact same line of shooting -> likely dead. Count the time units the ailen might consume until the shot happens and match your distance to the corner and RF mode to that, so that the shooting distance will be ideal. The plasmablaster ball deals splash damage, since it hurts the soldier himself, it won't be fired a range of just 1 field. A sheevar should die from plasma rifle 3-round burst for instance.