With some software (Go code that is always statically linked by the official toolchain comes to mind) you are shooting yourself in the foot with GPL and even LGPL.
It's complicated. To be able to modify, recompile and relink the LGPL part you would have to use the exact version of the go toolchain with which the commercial part was compiled with. Not to mention having to come up with a custom build process that puts the object files in the distributed archive...
With some software (Go code that is always statically linked by the official toolchain comes to mind) you are shooting yourself in the foot with GPL and even LGPL.