My take on it is that if he's spooking & spinning under sale then he may as well go out in a small paddock because he's unlikely to do more damage there than ridden, it's safer for everyone & he'll relax and after a few days a lot of the trouble will be gone. Yes a bit of sedation to start with may be wise, but you're now at the point where you need to look at the whole horse not a specific problem (and this is something some vets seem to find hard). Ultimately he's your horse & you do have a say, the vet may advise that more box rest with controlled exercise is the ideal for his problem, but you have every right to override that & say the Ben you know needs to be out before he does himself & his rider an injury.
Good luck for tomorrow.