It is best to statically build golang via an external toolchain. However, I hope your Golang version has been patched to work correctly as Fork and virtual memory are rather... obese. 
Runtime shrinking should also be important to you as well on memory/storage constrained devices too.
At the end of the day what we did was create a local feed with a local package. Jenkins builds the binaries as a seperate project and inserts the build products into the local package. The LEDE package makefile has an empty, compile directive installs it into the rootfs/firmware. This works for us, but it is... less than ideal.