I did some tests and you can change config values of that script.
You could for example use it to change config values with a chat comand instead of havig to do it through the web interface.
But at this time for some reason the set value can't be accessed right away (at least from my testing). The script has to be reloaded first or the value has to be set like a variable.
Usage is pretty easy:
Code:
var engine = require('engine');
engine.saveConfig({keyName: 'value'});
engine.log(config.keyName); //before reload: logs nothing; after reload: logs 'value'
config.keyName = 'value';
engine.log(config.keyName); //logs 'value'
config.keyName = 'test'; //'test' doesn't get saved to config but as variable
engine.log(config.keyName); //logs 'test'
PS: Sorry for late reply but I hope I helped someone.
Edit: Tested version was 0.9.16-10f0fad