Unfortunately, we're still mostly in the dark about how this works. Because at the higher levels, there was talk about it degrading your rep unless you kept it up.

But with how much renown it's going to take to get to level 20 (is probably going to be 100,000 or more. Might even be 1,000,000). I just don't see how kobold farming would be productive. There has to be some way to get some guaranteed amounts of renown.