consider this just a suggestion, it will be interesting to define for a top down implementation or implement prototypes of large apps and scalable enough to define some functionality in f# to later redefine and fine grain entities and to define in f# C#
or VB NET each biztalk orchestration or workflow case and make it compatible with the same functionality implemented in f# or C# or VB NET so installation of orchestrations workflow and BC code are less coupled and its more scalable for microsoft azure platform