Hi! Not sure this is a good idea but I implemented binding macro for Squint: https://github.com/squint-cljs/squint/pull/646
The reason why I am hesitant about whether this is a good idea or not to include in Squint is that JavaScript doesn't have a concept of a variable being dynamic. Also, maybe with-redefs would be a better name for this kind of macro? Not sure.
A big caveat with binding and ES6 modules is that it only works within one and the same module, since you can't alter "vars" from other modules. This is why I haven't included it in squint (yet).
Oh, I see, thanks for the clarification! I will close the PR for now.