> Additionally, the reflow cost post-execute will be <100ms It really depends on the page. It's pretty easy to come up with pages that take a lot longer than

> Additionally, the reflow cost post-execute will be <100ms It really depends on the page. It's pretty easy to come up with pages that take a lot longer than that to reflow (tables, deeply nested flexboxes, etc). I agree that typically making the script async is a good idea, but it's really worth measuring both ways for the particular script and page in question.