Very shameless plug on your last "Edit:", but I think it fits perfectly one feature that a web extension I made does: https://webcursors.click/.
There's a feature to write a note and leave it on the page for others (with the extension installed) to see and maybe have luck someone contacting you.
The design on your site reminds me of kinopio.club, I like the sort of whimsical style that doesn't compromise on utility.
> There's a feature to write a note and leave it on the page for others
Your site says that "nothing is stored." Does writing a note require everyone to be on the site at the same time? At first I thought it was sort of like the old "Dissenter" extension that added comments sections to every page, but the description seems to indicate a more live chat style.
There's a feature to write a note and leave it on the page for others (with the extension installed) to see and maybe have luck someone contacting you.