as @user85421 mentioned, using unicodes won't make the escapes unrequired, as I though it would.

so, escaping (, ), [ and { is still required, here's the fix:

    private static final String MATCH_OPENING_BRACE = "\\\u0028";
    private static final String MATCH_CLOSING_BRACE = "\\\u0029";
    
    private static final String MATCH_OPENING_SQUARE_BRACE = "\\\u005B";
    private static final String MATCH_CLOSING_SQUARE_BRACE = "\u005D";
    
    private static final String MATCH_OPENING_CURLY_BRACE = "\\\u007B";
    private static final String MATCH_CLOSING_CURLY_BRACE = "\u007D";