The main motivation wasn't a particular C++20 feature, but using GCC, Clang and MSVC as a portable optimization and code generation backend instead of LLVM or custom machine code generation.
As for coroutines, no. Clx doesn't use C++20 coroutines because Lua coroutines are stackful, so the runtime uses platform-specific context switching instead.
The main motivation wasn't a particular C++20 feature, but using GCC, Clang and MSVC as a portable optimization and code generation backend instead of LLVM or custom machine code generation.
As for coroutines, no. Clx doesn't use C++20 coroutines because Lua coroutines are stackful, so the runtime uses platform-specific context switching instead.