@amoser : I’d be interested in this video tutorial as well, if it’s still online. Feel free to PM me if you can.
I’m having issues with alembic geometry caches and motion blur too.
The thing is that disabling motion blur (in Project settings) fixes most of the bug, but there are still small artifacts whenever the player starts moving. I’m quite at a loss, so I’m now thinking of writing directly to the velocity buffer as it seems the issue is velocity-induced. I have no idea about how to do it in Unreal Engine though. 