The European Union and other advanced economies are turning to mandatory due diligence regulation to address environmental and human rights risks in their global supply chains. This shift is accompanied by calls for ‘smart regulation’ that combines public legislation with private governance instruments and new supporting measures in the producer countries of the Global South. We study the smart regulation agenda in the case of the European Union Deforestation Regulation. We reveal how its progressive rhetoric masks a conservative undertone as business actors and their civil society partners aim to safeguard their vested interests in the age of public supply chain regulation. However, by tracing their lobbying efforts throughout the policy formulation process, we show how this does not imply en bloc support for voluntary, softer forms of regulation. Moreover, these actors exhibit varying motivations and preferences for involving Southern actors in such a mix. Consequently, rather than forming a cohesive policy coalition, their preferences span from conservative to progressive, resulting in new alliances and divisions in this time of regulatory change. By untangling the complexities of ‘smart mix politics’, this article advances critical research into the evolving role, positioning, and influence of business actors in global supply chain governance.