Ivan while what you describe works, but it is just temporary fix for some other problem.
If holes in headstock are misaligned the posts are being pushed to side which creates extra friction in two places. First is inside bushing, but since most bushings are quite loose it requires really bad misalignment so the post gets jammed in there badly. The other, and IMO, more sensitive spot is at the mounting hole in the tuner plate. The post has shoulders that rest against underside and on the other side it's the bottom of teh cog wheet that sits on the plate. The two parts are machined so that when the parts are solidly held together with the screw the gap between the surfaces is slightly larger than thickness of the tuner plate. On most tuners (except the very cheapest ones) the extra space is occupied by spring washer that creates slight tension so the parts don't wobble in the hole. I just had Waverlies apart today as one tuner was slightly hard to turn and they have (rather cheap looking and roughly made) sping washers under the cog wheel that tend to abrade small circle under the cog wheel with their sharp edges, I had to clean the dust and lube it so it worked smooth again. Even when the screw is fully tightened you can feel some play in the assembly due to spring washer. On the GA tuners the washer is under the plate on the shoulders of the post (which I find better design than what is on Waverlies) and there is a bit more noticeable play in the assembly when the screw is tight. On Schallers there is specially shapes spring washer under the cog wheel with tab that extends below the worm and holds it in place.
Now back to topic. If holes are misaligned the worst part of friction comes from between the cog and the plate (due to leverage of the post in the misplaced bushing) and slackening the screw loosens the friction but that's not what the screw was intended for originally (reminds me how guitar players lower action by tightening the truss rod - it works somehow but it has some other adverse effects and real lowering of action should be done on bridge side only), loose screw will cause that the cog wheel no more meshes in proper alignment with its worm and the gear may get worn out prematurely. And since the cog wheel and post rides not square to the plate the edge of the wheel (or the washer) will dig into the plate surface and wear out deep circle (often seen in vintage tuners since they are of rather soft metals).
As I said before the worm gears are one of the simplest things from the machinist angle of view but to work properly the alignment must be adhered to.
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