And the definitive answer is... Sometimes.
Different games it works great to use the stop feature, some it has no advantages at all.
The question here is in whether hitting the stop button alters the outcome or frequency of winning spins. it takes some practice but in a nut shell I can consistently (8-10) hit bonus rounds in games like
Hidden Riches,
London Inspector,
Green Light and
Achilles. Also do well with Paydirt,
Coyote Cash, Ceasers Empire,
Honey to the Bee, and
Haunted Opera.
My method involves watching the screen and stopping the reels the second my mind caches the flicker of three or more bonus/wilds on screen at same time. This is not to hit on that stop, just to "freeze" the reels in a likely configuration. Then with two to three spin/stops for those reels to pop around there is the bonus .
If you watch any individual reel you will see the bonus/wild cycle through on a consistent pattern. each reel has its own pattern and spin speed so I can usually "set up" the bonus by stopping a reel after the first reel stops on its own allowing the next reels to advance to a bit of a different configuration.
The whole point is it takes practice. For me, I went into free mode and spent a couple hours of stop and go playing on a variety of games until I felt comfortable trying it out for real (well a free chip, I am not completely insane). It worked and I made the playthrough. Tried another free chip at a different casino... made the playthrough.
So to sum up, yes I do believe you can influence, to some extent, the outcome of spins based on using the stop button... But it is influencing a
future spin... not the one that is spinning.