The GE models that don’t require a neutral have been discontinued by the manufacturer, but you can still sometimes find them.
Whether they’ll cause LEDs to flicker depends very much on usage and the specific fixture (not just the switch) which is why they’ll work for some people and not others. Usage is because some set ups get flickers at full on while others get flickers at about 20% and lower. If you only dim between 50% and 90%, as many people do, you may never see the flickers.
So the switch may be acceptable to some people, not to others, and it’s impossible to predict in advance which is why GE discontinued them.
Cooper still makes a zwave dimmer switch that doesn’t require a neutral and is intended only for incandescents. All the same issues apply. Some people will be happy using it to control LEDs, some won’t, just depends on the fixture and the usage.