This is a common question in the forums. I know it can feel really frustrating, since most of the available switches do require a neutral to power the radio. There are some zwave options, but it’s important to note that all of the dimmers that don’t require a neutral are only rated to work with incandescent bulbs, not LEDs.
Lutron use a proprietary patented method that does work well with most LEDs and doesn’t require a neutral, but as you noted there’s no direct integration with SmartThings. You can get indirect Lutron integration using IFTTT. However, this method introduces some lag, and the amount of lag varies from person to person. At my house it’s about eight seconds. That’s fine for lights that are on a time schedule, but would typically be too long for lights that were triggered by a motion sensor.
All of these have matching auxiliary switches that can be used in three or four way set ups.
The following thread discusses the specific options: