Wading through the massive literature on deontic modality paid off and there are now two papers on deontic modals and conditionals forthcoming in very fine places:
Dynamic Foundations for Deontic Logic, forthcoming in a volume of papers on deontic modality, edited by Nate Charlow and Matthew Chrisman and published by Oxford University Press
Dynamic Thoughts on Ifs and Oughts, forthcoming in Philosophers' Imprint
Abstracts and final drafts are available in the Research section and the final publication information will be posted as it becomes available.