The knobs aren't on the GC necessarily, rather language features.
With a Go compiler toolchain you have stack and global memory static allocation, use of compiler flags to track down when references escape, manually allocate via OS bindings, there is the unsafe package, and use slices with it, an assembler is part of the toolchain learn to use it, and regardless of CGO is not Go memes, it is another tool to reach for if Assembly isn't your thing.
Ohh right yes, now I get what you mean. My brain just immediately went for "GC knobs" when you mentioned "knobs", but in my defense I'm running a 40°C fever so I should probably not be commenting at all
