I admit that I'm quite curious about determining exactly what features could be left out of maximally-explicit Rust, because it would determine the obvious MVP for an alternative compiler, that could technically compile all Rust code with the caveat that you would need to first losslessly and automatically transform the source (which theoretically shouldn't be too hard to add the Rust compiler, e.g. it already has the capability to print Rust source post-macro expansion). Without macros, you'd need neither an implementation of pattern macros nor syntax extensions; without inferred types, you'd need neither a trait resolution engine nor anything of Hindley-Milner; with every identifier fully qualified you wouldn't need any name resolution rules... and we've already established that a borrow checker is unnecessary to implement if your goal is to merely compile Rust code that has already been typechecked. All that together means that you could have a legitimately useful alternative backend with so, so much less work on behalf of the implementor!
