FWIW, papers that focus on implementation are (slowly) becoming acceptable in the compilers community. However, like you mentioned, novelty is essential.
The arxiv is another possible option for implementation papers (if you don’t mind piggybacking on another CoRR category like architecture or programming languages).
The arxiv is another possible option for implementation papers (if you don’t mind piggybacking on another CoRR category like architecture or programming languages).