From version 2.9 Alpha (Plus) b1700+ you can download and upload the Server configuration file (config.xml) through the Admin Web interface. You can then use Omniscope (free viewer too) to edit the config.xml file.
Go to the Admin Web App main page and click on "Server Configuration"
Then you can 1) Download the current server configuration file (config.xml) 2) Edit it locally with your Omniscope app (feature available in "Settings > Server > Edit server configuration" menu). 3) Upload the edited/new config.xml . The Server will apply the new settings and restart its services (e.g. Scheduler, Mobile Web Server).
Once uploaded correctly, the UI will show a confirmation message. N.B. if you change server global settings like log folder, log level, you will need to restart the Omniscope Server app.