Since the audit failures of the early 21^st century and the enactment of SarBox, auditors have been prohibited from providing ancillary services to audit clients (with the exception of tax services):

What obvious post-SarBox required element of an audit would provide the most "insight beyond the opinion"? 

Are audit clients looking for a "backdoor" to securing "management advisory services" through the audit?

 Is ESG reporting going to be an ancillary service that is allowed for the auditor to provide?