I think this is not a requirement for final release but StaticScope naturally deals with variable allocation and scoping rules. It even takes care of shared explicit binding local variable allocation. Originally, the motivation was to have IR model this stuff separately. A large part of that motivation was it existing besides our old runtime. This allowed us to make changes to lvars without needing to consider the second runtime. Now that we only have one we should make any tweaks needed and just use StaticScope.