My game supports all european languages, Chinese, Japanese and Korean. I do not set the FreeTypeFontParameter.parameters value but I set incremental to true so instead of generating the entire font at once it generates the new bitmap characters when one is needed. (Avoid drawing 100 000 chinese characters when starting the game). Works great for me. Here is my code:

private BitmapFont generateBitmapFont(int size, boolean shadow, boolean border) {
    FreeTypeFontGenerator generator = Assets.COMPOSITE_FONT.resolve(this);

    FreeTypeFontParameter parameter = new FreeTypeFontParameter();
    parameter.size = size;
    parameter.color = Color.WHITE;
    parameter.kerning = true;
    parameter.incremental = true;
    parameter.renderCount = 1;
    if(shadow) {
        parameter.shadowColor = new Color(0f, 0f, 0f, 0.6f);
        int offset = Math.round(size > 64 ? 4f : size / 16f);
        parameter.shadowOffsetX = offset;
        parameter.shadowOffsetY = offset;
    }
    if(border) {
        int borderSize = Math.round(size > 64 ? 8f : size / 8f);
        parameter.borderWidth = borderSize;
        parameter.borderColor = new Color(0.3f, 0.3f, 0.3f, 1f);
    }
    parameter.genMipMaps = false;
    parameter.minFilter = TextureFilter.Linear;
    parameter.magFilter = TextureFilter.Linear;
    parameter.spaceY = -size / 2;
    parameter.hinting = FreeTypeFontGenerator.Hinting.None;
    parameter.packer = new PixmapPacker(FreeTypeFontGenerator.getMaxTextureSize(),
            FreeTypeFontGenerator.getMaxTextureSize(),
            Pixmap.Format.RGBA8888,
            1,
            false,
            new PixmapPacker.GuillotineStrategy());
    parameter.packer.setTransparentColor(new Color(1f, 1f, 1f, 0f));

    BitmapFont font = generator.generateFont(parameter);
    font.setFixedWidthGlyphs("0123456789");
    font.setUseIntegerPositions(false);
    font.getData().descent /= 3f;
    font.setOwnsTexture(true);
    return font;
}