Don’t worry, Breww does have a record of all transfers, so the data is there. It’s just not currently exposed in a report. We’re busy with other tasks at the moment, but we will get to this report when we can.
Voting for the feature request will help with its ranking in our internal reports too 
I think you may find Stock transfer between sites/contract brewers/offsite packagers on delivery schedule (Stock Movement Documents) worth voting for too.