There's no chance of this reaching 720pph most of the time, it involves kids which always slows things down but also the dispatches would have to be ridiculously fast all the time. If this had a turntable and a second train you'd be looking at something just over that, so I doubt it's going to get that. Then again it is B&M so I'm sure it'll be engineered to be able to have a good capacity, it will all revolve around how the park operates it.
With regard to the bolded, I don’t think that’s necessarily true.
With a 24-rider train, 720pph equates to a dispatch every 2 minutes, or 30 trains per hour. The planning application states that the ride will be 1 minute long, and the load/unload time will be 1 minute as well in order to attain this throughput. I’d hardly call 1 minute a ridiculously fast park time that wouldn’t be attainable over a long period. As I said, Swarm at Thorpe attained a similar load/unload time to this in the operations video I posted above, so I reckoned this would be perfectly attainable at Chessington with a train that’s one row shorter.
If the ride had a turntable, switch track or similar mechanism that accommodated two train operation, I reckon the theoretical would be 1,440pph (a dispatch every minute, or 60 trains per hour) or somewhere just below, because the ride duration and the park time would be occurring concurrently rather than separately (one train would be loading and unloading whilst the other was going round the ride, whereas on one train operation, the station would be totally empty whilst the train was going round and the load/unload time is added on top of the ride duration), thus roughly doubling the throughput.
One question I do have is; why do we assume that more children will be riding this than Swarm? I know Chessington has a younger visitor demographic than Thorpe, but it will have the same height restriction as Swarm (thus limiting the ride’s audience to older families and adults by default), and Thorpe does have older families visit it, so it’s not like Swarm won’t have older children riding. I’d also wager that children who are 1.4m in height will likely be old enough not to cause any major holdup to operations in the way that smaller children might.