In the UK some constituencies compete to be the fastest 48 mins after the close of polls
There are normally multiple observers from all parties, plus election officials, that scrutinize the counting process in real-time. Disputes are raised and resolved on the spot where possible, and it not are normally escalated. This is why elections can have provisional results on the same day/night, and the official results are a few days later.
The extent of the competition over seconds and minutes here is bound to lead to some mistkaes, and I would question whether the checks are sufficient (the checks themselves may also be susceptible to mistkaes). The word "childish" comes to mind. We are talking about the future of the country and it's treated like a TV reality/quiz show.
That seems very odd. Can you actually do that? Around here the polling location must first ensure that the number of votes cast matches the number of votes recorded during voting, only after that can they open the urns and start tallying.
PS: Saying you need to change the law when that must happen with any significant change anyway is kind of a minor hurdle.