Those are interesting observations. When doing something like `let rec loop ...`, I got into the habit of using parameters for only those entities that might change from one iteration to the next. The rest (as being constant / invariant across iterations) dwells in the closure env, if only for the sake of making the source code shorter. The article shows nicely how this obvious mental shortcut has its (equally obvious) costs.

It's also a nice practical demonstration of how reading disassemblies is still an integral part of understanding a language, even this relatively abstract ML descendant.