Emoji only show 'blank tofu' symbol when exported as PDF

[Snuggle]

👋 Hello!

When I export my CV as a PDF, all of the emoji seem to turn into broken 'tofu' symbols. This is not an issue with the HTML format.
Would it be possible to include some kind of emoji font to exported PDFs to fix this issue?

Here is the command I am using:
resume export public/index.html --format html --theme rocketspacer; resume export public/index.pdf --format pdf --theme rocketspacer

Example Screenshot from Exported PDF (Broken)

(It is worth noting that the font-awesome style icons are fine, this issue only affects native emoji)

Example Screenshot from Exported HTML (Working)

[Snuggle]

I have tried adding <script src="https://twemoji.maxcdn.com/v/latest/twemoji.min.js" crossorigin="anonymous"></script> to a theme's stylesheet but it made no difference. From some reading, it seems like PDFs don't support SVGs in fonts, which breaks multi-colour emoji.