But he mentions he wishes he could start dynamically and end statically. By enabling Flow at the end, don't you basically achieve that? You can also enable it

But he mentions he wishes he could start dynamically and end statically. By enabling Flow at the end, don't you basically achieve that? You can also enable it progressively for files as you move on, and still rapidly prototype without it. In fact, unless I'm mistaken I believe it's "opt-in" by default, ie. Flow won't scan the file unless you include the special comment keyword at the top of the file.