We have now tested building command-line binaries with gcc 6-11 and clang 6-14 and verified command-line binaries can be built.
Some warnings were fixed while others were suppressed if deemed non-critical. We still target C++-17, so newer compilers might issue warnings about code that is valid for C++17 but not later standards. Later standards have removed some functions that are essential for proper operation.
ClangCL is still not supported as it will issue so many warnings that standard clang doesn't and Boost libraries still have limited support for ClangCL.