How to force binary hash algorithm in Ensemble production?

TL;DR: If I set an Ensemble  Production Service based on EnsLib.File.PassthroughService to a Binary charset encoding, it breaks the file handling. Any ideas?

Full long post:

All,

I set up an Ensemble production to transfer files via SFTP, which works fine sending the files to my Linux server. Then I was informed that we needed to save a hash of the file, for comparison with the destination to verify the file arrived unmodified. I looked at the base64 encoded hash on my linux server:

G7QWAP6FcLInFWP8ECRL/EI2NfKdaf6TtrpwYuvSOEc=

and I created a class to extend the StreamContainer to add a hash value:

which seems to work fine. But when the production runs, the hash is listed as:

Vn0ygZZN8DewD8KfKKYF8BTV9K1LsuFBEXnAkqXBEFs=

I narrowed that down to Ensemble automatically choosing the stream type - in this case, it sees it as a FC type stream - File Character - but Linux sees it as a Binary encoding. I verified the issue with this bit of code:

And when run, here's the output:

ENSDEMO>D ^HASHCHECK
Binary: G7QWAP6FcLInFWP8ECRL/EI2NfKdaf6TtrpwYuvSOEc=
Char:   Vn0ygZZN8DewD8KfKKYF8BTV9K1LsuFBEXnAkqXBEFs=

I found a setting in the EnsLib.File.PassthroughService  to manually set the charset to Binary, and when I set that, the production will give me the correct hash and sends the file - but then recreates the file with a randomized OriginalFilename, waits 5 seconds (or whatever's set in the Retry Interval parameter), and sends it again... and again... and again.

When I look at the message viewer, the <Stream></Stream>  is empty:

 <?xml version="1.0" ?>
<!-- type: SFTP.HashFile  id: 281 -->
<HashFile>
<OriginalFilename>C:\Export\aPvlvsYdsoNpng.CSV
</OriginalFilename>
<Stream></Stream>
<Type>FB
</Type>
<Attributes>
<AttributesItem AttributesKey="1" xsi:nil="true"></AttributesItem>
</Attributes>
<Hash>G7QWAP6FcLInFWP8ECRL/EI2NfKdaf6TtrpwYuvSOEc=
</Hash>
</HashFile>

Even though file is sent intact successfully.  (You can see an example of the 'random' filename above.)

Any ideas that would be easier than rewriting  a custom EnsLib.File.PassthroughService and/or Ens.StreamContainer to only handle binary encoded streams?

Thanks for any and all input!