Let's say I am working on two, similar projects, on two separate grants with collaborator A and collaborator B. In the process of working with collaborator A, I came up with an idea for a new project which I am now working on based on ideas from collaboration A. Collaborator A will be a coauthor on the first manuscript on this new, tangential project, which will also acknowledge their grant.
However, I believe collaborator B would be much better suited to carry out this project in the future. Furthermore, I do not believe collaborator A is interested or competent in continuing my project. When and to what extent am I able to share the preliminary results carried out in my project with collaborator B? Should I wait until the manuscript is published? Am I breaking an implicit information embargo? (I came up with the idea for the project and carried out all the theoretical work. Collaborators A and B are experimental scientists.)