It’s been discussed. And apparently the problem is that Harmony has a rule that no remote operations can be used for activities that include locks. And it looks like smartthings is viewed as a remote operation (as also is IFTTT).
So you can set up the harmony activity that includes an August lock. But you can’t have smartthings trigger that activity.
If you have all the pieces go ahead and try it and let us know if you see anything different.
Smartthings issue with the api is that it does not show the current status of the lock but the ability to just send the lock or unlock command would be huge compared to not being able to to anything at all… Harmony hub and Yonomi and currently doing this. A small win is better than no win…