Neat idea!
Fun fact; it's not as widely usable but data URLs work for this too.
Maybe you could add an option to copy the data URL for a page?
e.g. this one
https://bigwords.page/#%23%20Gate%2012%0ABoarding%20now&bg=0...
becomes
data:text/html,<!doctype html><meta name=viewport content="width=device-width,initial-scale=1"><body style="margin:0;height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;background:%230b3d91;color:%23fff;font-family:sans-serif;text-align:center"><h1 style="font-size:18vw;margin:0">Gate 12</h1><p style="font-size:9vw;margin:0">Boarding now</p>
(paste this ^^ into your URL bar)
Neat!!! Does this work with mailto, can you embed html into emails?
You can set the content of the mail, whether it accepts html is up to the email clients I think.