[cbolton]

Could it be an illusion because the "zoom" is a bit different? (I was screenshotting different applications).

Here's a better comparison: 11pt size for both, then importing the LaTeX output in typst (using SVG conversion since typst cannot import PDF): https://imgur.com/a/aZRx6fs

I removed the "comma" that produced different spacing, and added the missing F_n. It seems there's still some different in spacing due to the quad.

If you still think the spacing around '+' is different you'll have to add some highlight/measurements or something to convince me, because they look quite identical to me...