An audit regime is what defines the terms used in an audit. It includes at least the styles of capital and full cost accounting and activity based costing rules that are supposed to be obeyed in a system.
Investigative integrity is what makes an audit different from other deep investigations, and makes it more like the scientific method which is the highest integrity way of mutual cognition anyone on Earth knows how to do.
To build moral cognition suitable to do moral purchasing on top of this is difficult, and requires a degree of definitive integrity as well to get the terms of reference right. Many of these terms are factionally defined and subject to politics as usual. This is probably the worst design problem in ensuring that the Consumerium buying signal is accepted by all as actually reflecting their own individual buying criteria.
To build this trust, the audit regime must focus only on the base terms that are at least less subject to politics, and which aren't influenced by political choices directly. When the audit regime establishes that something is trustworthy, all factions must believe it. Thus they must add any issues they have to the audit regime in advance, and accept the results. Each aspect of the centrally controlled information economy within Consumerium has to have elements of the audit regime to deal with it specifically, and more to knit it together for various audiences or groups that are concerned with how it works.
Audit regimes are the only reason anyone believes that, for instance, emissions trading or stock markets might work. If indeed they do!
In Transparent Consumerium, theoretically, anyone could do an audit, and there would be no need for an audit regime run only by the Consumerium Governance Organization.