Stiff Hipshot Ultralite tuners - any suggestions on making them turn smoothly?

Have you tried adjusting the tension control screws to loosen the feel of the keys?

 

Try loosening the tiny Allen screw at the bottom of the post. I think it's a 1/16" Allen key. A small adjustment will make a big difference so go slow.
Be VERY light with the lube. I use plain old petroleum jelly, just a drop on the end of a toothpick is enough to do one tuner. Maybe once a year, if I remember it.
Too much lube gets gunky over time and can make matters worse.
B.

 

The licensed Hipshots don't have the tension screw if I remember correctly. They are reversible when they do have it.

 

Both the US and licensed components have the tensioner cap screw.

Riis