My unit is a Harman, and he wasn't sure it was going to work so I offered to pay him whether it worked or not. He did mention the risk of bricking my unit, which would have been... terrible honestly. If you want to use ODIS offline (for guided functions) then the VAS5054 is useful. Not sure it's useful for anything else though. I haven't used ODIS but my understanding is that VCDS is much easier, almost as powerful, and equally as useful for most of us.
I replaced my low BCM with a high. Long coding is easy enough but there are 1,000+ adaptations that you would need to manually re-enter. There's also CP to deal with and pairing of key-fobs. My dealer quoted me 4 hours. They also screwed it up (didn't pair my key fobs, didn't do adaptations, etc.). It took me multiple visits to get everything sorted, involving a call to VW engineering and a call to a local Audi dealership. At one point they told me I needed to re-install my stock headlights and tails so they could troubleshoot the faults they were seeing. In actuality, they were seeing faults because the BCM came with adaptations set for a car with lighting package.
In the end, all they actually needed to do was follow the ODIS guided function for a BCM replacement, from beginning to end. I don't know if they chose not to follow the function or didn't know how to follow it, but either way it was a s*** show. I only paid their quoted labor although they probably put 20 hours into it. VW only stock's high BCM's so their process for replacing mine should have been no different than if a customer came in with a bad BCM.