IR35 where to seek expert advice

Despite our work last year on IR35 where most of our contractors fell outside of IR35, after reviewing them on CEST tool today we're now getting an 'unable to determine ' result in most cases. I understand the tool is continually updated as case law determines the responses but this has thrown us. I feel unable to advise the Company without an expert assistance at this point. Has anyone used an external service from the 'hirer's' perspective and was it worth the fee?