Possible to have watched folders?

It is-have you tried it yourself?

Bluefrog suggested four ways to update the contents of a selected indexed group:

  1. You deselect / reselect it (the indexed group)
  2. Use File > Update Indexed Items
  3. Option-Command-S
  4. Add the Update button to your Toolbar, it will query and set the new state.

Additionally, I don’t know if you have browsed in the Tips, Tricks, and Troubleshooting section here (this particular forum is more appropriate for reporting feedback and feature requests), but I have a post pinned to that forum that discusses some useful information when working with documents outside of DEVONthink. You can fine it here. Note that the discussion took place before DEVONthink to Go version 2, so I expect you could pretty much disregard any discussion of that app in the thread.