@Geez that I can not quite agree with, given how DayZ has utf8 support because of the launch in China so it supports Chinese utf8 chars. I would be surprised if it was only present in DayZ's engine fork. Please ask for clarification again.
The only possibility of the answer being true ist if the utf8 versions in DayZ are sham and do not actually work/do anything and its just the default WANSI strings operations under the hood.

I'm pretty sure scripting supports UTF8.. You can set UTF8 string to UI widget text.
And you get UTF8 string back from UI widget text input fields.

In T173104#2456885, @Arkensor wrote:

@Geez that I can not quite agree with, given how DayZ has utf8 support because of the launch in China so it supports Chinese utf8 chars. I would be surprised if it was only present in DayZ's engine fork. Please ask for clarification again.
The only possibility of the answer being true ist if the utf8 versions in DayZ are sham and do not actually work/do anything and its just the default WANSI strings operations under the hood.

Further clarification from the responsible dev:

Game UI and language database text supports UTF8 (both Reforger and DayZ), but script string do not support UTF8 (in both Reforger and DayZ). Fact that in DayZ branch there are two methods which working with UTF8 (SubstringUtf8 and LengthUtf8) does not mean there is support of UTF8 and does not mean that they must be ported to Reforger.

I feel bad for making you play Messenger here, but I would like to point out to the responsible dev that we need support for in script because we can as he said, have utf8 in the UI, and thus we need to handle utf8 chars that appear in the setter or getter code when interacting with widgets, or things like player names or chat messages that have utf8 characters. Declaring that string myutf8string = "Hällö fröm the öther Sßide こんにちは世界" can not be possible or even worse - is not needed - is not comprehensible for me. If there is no support for it right now then it should be added for sure.

Hello Arkensor.
While the dev has read this and there was a discussion in regards to this topic internally, at the moment there are still no plans to introduce utf support in scripting.