The website is open-source, though currently entirely static…IIUC to do those changes it would have to no longer be static :/
Ok, next on my wish list for these /email urls:
1. Change title to: "Send sats to [email] (BIP353)"
2. Check if there's a gravatar and set it as
https://gravatar.com/2ef4e86a6b0e3ba9680897801bdbc6e0d8a497948e764837a0198c63e93f1b6f 
Discussion
Both can be done with javascript Dom manipulation. Most web crawlers will do some basic javascript these days, though I haven't tried this tag.