You can reserve only when you are connected to the BIM Server.
I think you are right, if you sent him this Travel Pack he would be seeing your (User A) reservations.
One thing you could try is use TeamViewer or some other screen sharing program. Connect him remotely to your desktop, let me Sign in to the TW project as User B, with his own password, reserve items he needs, then leave the Project (only Leave, not Sign Out).
Then you could save a Travel Pack for him. That might work, but you will have to try it.
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