Thank you @daibaron. My goal is similar to yours; have an updated release for the Linkstar H68K-xxyy, to have better hardware, software, and security functionality for it.
A related goal is to get that work into the main OpenWrt tree; to do that, it looks like work needs to be done upstream in the kernel and u-boot code to support the device. If that support for the H68K makes it into those code trees, then the path to acceptance into Openwrt's main distribution is much easier (based on my look at commit comments in openwrt for earlier work that didn't get accepted).
Also, see my update on the BPI-r2-pro