This feature request came to my mind as our company registered a few IDN domains. I'd like to add that IDN domains are a thing now, and should be supported in Aegir so I thought why not.
I created a simple script to convert between Unicode and Ascii with the "Add a site" feature, I'd love to see this in the core but I couldn't get hosting.inc to match the domains :\ I guess the problem is with the domains containing multiple dash's? So as in RFC the domains would be served in the databases and config files in their respected ascii equivalent.
ääkköset.fi <-> xn--kkset-fraa0m.fi
Please see the attached patch proposal for hosting_site.form.js to target converting of the domain names with change of the input fields focus.
Kind regards Ilari Lind