I get what you are wanting. However; BW is a zero knowledge storage method and the vault MUST be open to even access it let alone export it. I see where your suggestion was to leave it open in order to transfer at some designated time in the future. I would never do that. BW has an immediate lock for those times you need to leave a computer unattended. By locking the vault you are NOT logging out, merely locking it with a strong PIN (mine is alpha-numeric) code. That alpha-numeric code can be somewhat long. I use 6 digits but it could be longer. If someone were to sit at my computer and start attempting to hack in by guessing my alpha-numeric PIN the software gives them “5” attempts and then the BW vault is automatically completely logged out. You are not going to guess my random 6 digit alpha-numeric PIN in 5 attempts unless you are the luckiest person on the planet.
I feel this feature can abate your fears and is very easy to employ. My .02
I do typically use the quick-lock but occasionally forget, and if I’m sharing my computer with someone on a task it’s a bit rude to grab my computer and lock BW before I go to the bathroom or something. A timeout feature wouldn’t need to be verified server-side or do anything fancy to provide a decent security increase.