Creation of Bval bvec files

Could you add an example about how to create multiple bval/bvec files within a session?

Use case:

in some protocols (COGNAP, IRONSLEEP, STR7T, etc), on top of the regular DWI sequence, there is an additional sequence with reverse PA. Although the bval/bvec files associated to that additional sequence are trivial (bval=0, bvec=0) and thus easy to create manually, it would be nice to be able to create them when bidsifying. Current issue:
in most examples of the prepare_plugin I have seen, the bval/bvec variables are declared (global) and initialised in the SessionEP function. Then filled in the FileEP function and written in a file in the SequenceEndEP.
with this current implementation, the bval/bvec variables contain the values for all the DWI sequences (regular+additional).

Having an example about how to proceed to have a separated bval/bvec file for each DWI sequence would ease the project-specific plugin implementation.

Thank you.

Cheers,

Greg