I suspect that a cordless angle grinder would have difficulty with the lock and the attack would need to be on the steelwork to which it's attached, In any case, that's a lot of noise with potentially a lot of associated unwanted attention. FWIW, the Lock Picking Lawyer says that padlock "appears to be a pretty competent little lock", which is high praise indeed from one of the most skilled lock pickers in the business. IMO, the most likely way that entire van might get stolen is probably towed or on the back of a recovery truck!