Yes — you can now extend your E33G Remote Worker KITAS from inside Indonesia.
This is a fairly recent change: until recently, the only way to continue past the first year was to exit the country and file a completely new application.
We now handle onshore extensions for our clients, adding up to another 360 days to your permit without a mandatory exit. You'll still need to be in Indonesia for your appointment at the immigration office, but there's no need to fly out and back in.