I have been playing around with Unicode for a while and I found it somewhat reliable with the support of NI Unicode Library, as long as I don't write anything into the controls with my keyboard. In that case LabVIEW irregularly crashes after writing a word or sentence. I use Czech keyboard on Windows which has about 25 special chars so the keyboard output is one byte or two bytes depending on the char.
I would expect the Force Unicode option to fix it, and indeed, it outputs two bytes for any char with this setting. Though the display is faulty as seen in the image. Here is the string "čas čas":

Setting the property Text.InterpretAsUnicode with the Unicode Toolkit VI does even do the trick with the display:

But still the LabVIEW crashes after few non-ASCII chars. Has anyone made it work?