It will be impossible to ever truly do a one-to-one comparison. First, there may be a ton of code in the existing implementation that gets cut out by a mass rewrite due to better, more informed, architecture decisions. On the other hand, it may be possible that new features find their way into the rewrite that cause the fully Zig implementation to be larger than the original Rust-Zig implementation. I don't think any comparison will be fully "fair". A smaller implementation could be argued as only being possible in Rust or Zig because of its advantages over the other language. I expect results to be controversial.