Hi,
Our firmware is heavily modified so more or less it is updated, but it may not hold base functionality of Chaos Calmer version. We update our OpenWRT base with new upcoming updates, but mostly they're so heavily modified that you will not find a lot of similarities.
The best case would be waiting for base changing updates like we updated RUTX devices with RUTOS, so those might come with newer versions of OpenWRT even higher than Chaos Calmer.
EB.