The ignition shouldn't be a problem if you remove the knob and replace it in the same position. I keep my forks straight, turn the knob all the way to the left (lock), then remove it as per the prescribed method. If you have small hands you can use a small finger to push the tab instead of a screwdriver. You can then move the handlebars around as you wish, but stay away from the left full-lock position, then replace the knob mechanism in the same position you removed it. If you do that nothing should go awry.
The only time I had a problem was when I replaced the knob to unlock the forks after moving them too far to the left, but forget to include the spacers. By doing that the knob and tumblers were not in the correct position and I had to futz around with a screwdriver 'til I got everything aligned properly.