I'm in the process of working these exact same requirements.
- I'm still waiting to get a FTP connection established to pull BAI bank files. I've cloned the OneStream documentation supplied FTP BR to pull files once that connection is established.
- I have tested BAI files successfully as well with the BAI Parser and loaded bank workflows via the BAI Preview Upload/Import steps manually.
- I've started looking into a BR to perform the BAI file upload and Import into Workflow steps. I see the delivered BAI objects for those steps but I'm not sure I can replicate in a custom BR.
I would be very interested in knowing how things are going for you.
Thanks.