Given the dynamic rate of change in the OA books business models landscape, the OPERAS Open Access Business Models Special Interest Group launched a survey in 2021 to 1) improve our understanding of the scholarly publishing landscape and of the challenges that publishers face in the context of publishing OA monographs; and 2) to identify main trends (including opportunities and challenges) and the knowledge of collaborative funding and infrastructure models in OA publishing in Social Science and the Humanities. This white paper updates and expands an earlier version published in 2021, which presented the preliminary analysis of the findings. Despite a small sample of presses meaning that no strong trends ought to be discussed, several insights were drawn and should be considered important directions for the future. Key findings in the report have been grouped into three main areas: collaboration, funding, and support. The report found that, although not opposed to the idea, a majority of presses do not engage in collaboration, specifically collaborative models for shared infrastructure, mainly due to the lack of knowledge and information, or perceived lack of need. This indicates that, for OA books, we are still at the early stage of the adoption curve for collaborative shared infrastructure. In terms of funding, most publishers perceive themselves to be somewhat sustainable. For institutional publishers, parent organisations are crucial as providers of financial or non-monetary support of OA. In addition, most publishers stress the need to have more resources and rely on more than one funding source, including grants and subsidies. The report found that awareness-raising and targeted support and training could be used to engage the presses but further incentivisation may be required to encourage publishers to collaborate more widely. We believe that the insights from this white paper may be interesting to a number of projects, such as DIAMAS, OPERAS-PLUS, and Palomera and have presented areas for further research and more specific actionable points for these projects.