Again, there is no difficulty of any kind in using (say) Gcc-11 to build binaries to run on a stock CentOS 7 target. On CentOS (which user-space environment you

Again, there is no difficulty of any kind in using (say) Gcc-11 to build binaries to run on a stock CentOS 7 target. On CentOS (which user-space environment you would run in a docker image), I think the package you would need is dev-toolset-11. Look it up. (It is possible that is only in CentOS 8, so you might need dev-toolset-9 instead, which would serve.)