IDN is standardized RFC 3490 - Internationalizing Domain Names in Applications (IDNA) with ACE prefix (xn–).
And from year 2009 allowed and now widely used for example in EU TLD Introduction of Internationalized Domain Names | MPO
Without repaired bug “add IDN domain record”
in to user interface is not usable in Europe. I mean the unusable for general users. IT technician can use a configuration files, but then litle becomes meaningless use NethServer.