Exploding offers are bullshit (a meaningless scare tactic, almost never enforced) and you should politely but explicitly make it clear that you know this. At the offer stage, all the power is in your hands.
If you are a hiring manager, and this is policy, refuse to disrespect the experts you are hoping to entice.
If you are a hiring manager, and this is policy, refuse to disrespect the experts you are hoping to entice.