Hey @Viktor-Velicko,
Thank you for reaching out to us. Generally, our codebase supports Unicode, but in C++ source code and in *.str resource files, we only support Unicode escape sequences, not Unicode symbols directly. In Python, we do support Unicode symbols directly. In the 2025.3 SDK, I just added a code example for how to use Python to create a Unicode escaping pipeline around *.str files.
So, the Unicode string const String slopeLabel = "Slope 90º"_s; would be written as const String slopeLabel = "Slope 90\\u00b0"_s; in C++. A bit more verbose variant would be const String slopeLabel ="Slope 90"_s + String("\\u00b0", STRINGENCODING::BIT7HEX));. In Python, you can use the string directly as slopeLabel: str = "Slope 90°".
Cheers,
Ferdinand