The dashboard (currently) launches another editor to do the work, although I think it uses the standard mechanism to do that (the same as cooking, packaging, etc) although I never use DebugGame so perhaps it’s failing to pass the -debug flag to the new editor process.
Regarding String Tables, I wrote this up a while back and am still waiting for it to be converted into proper documentation. https://drive.google.com/open?id=0B6NVuVhmRCE-VGxVTW9iOUJUanc