Use language.iscustom

data/cdata/ui_scripts/settings/language.lua

@@ -83,7 +83,7 @@ LUI.MenuBuilder.registerType("choose_language_menu", function(a1)
 
     LUI.Options.AddOptionTextInfo(menu)
 
-    if language.isnonlatin() and config.get("language") ~= "czech" then
+    if (language.isnonlatin() and not language.iscustom()) then
         if (config.get("disable_custom_fonts")) then
             menu:AddHelp({
                 name = "add_button_helper_text",

src/client/component/language.cpp

@@ -125,6 +125,11 @@ namespace language
 		return asian_languages.contains(current());
 	}
 
+	bool is_custom()
+	{
+		return custom_languages.contains(current());
+	}
+
 	void set(const std::string& lang)
 	{
 		config::set("language", lang);

src/client/component/language.hpp

@@ -16,4 +16,5 @@ namespace language
 	bool is_slavic();
 	bool is_arabic();
 	bool is_asian();
+	bool is_custom();
 }

src/client/component/ui_scripting.cpp

@@ -239,6 +239,7 @@ namespace ui_scripting
 			language_table["isslavic"] = language::is_slavic;
 			language_table["isarabic"] = language::is_arabic;
 			language_table["isasian"] = language::is_asian;
+			language_table["iscustom"] = language::is_custom;
 
 			lua["language"] = language_table;