How does Cobrix writer behaves with FILLERs with VALUES clause?

## Background [Optional]
I've been trying to write a binary file containing multiple FILLER fields each with the following clause VALUE ','.
During my tests, and according to the docs, it seems that Cobrix ignores the VALUE clause and puts NUL instead.

## Question
How does Cobrix writer behaves with FILLERs with VALUES clause? Could it be possible to consider the VALUE clause as a 'default' value or there is anything else you would suggest to achieve the desired final file?