Why is OpenWRT version in gl-inet routers is a year old?

[pingpong]

@eli Similar thread (longer thread) over here as well. FYI.

Does Gl-iNet firmware get timely security updates from OpenWRT?

Please forgive me for what may be a newbie question. The firmware for my device is fully updated at currently 3.105, and the OpenWRT version on it is 18.06.1. Yet the current (old-stable) version of OpenWRT is 18.06.9, because there have been many security updates since 18.06.1. So does that mean that my device is not securely updated? Is 3.105 secure even though the OpenWRT version it is out of date? Or maybe those security updates up through 18.06.09 are somehow actually included in 3.105…