BUILD_PATENTED, shown in menuconfig as
Compile with support for patented functionality is disabled by default: https://github.com/openwrt/openwrt/commit/dc555d003c21679c8c94ac7f5c74cbd5cd089ae0. It may be required for some packages to run (see previous github link).
To learn more about what packages would need
BUILD_PATENTED run the following in the OpenWrt root directory:
git grep BUILD_PATENTED