The new gameplay is here, and from now on, the threshold will be completely lowered. A threshold of below 200 points should be coming soon.
In short, big penalties lead to big point deductions, and small penalties lead to small point deductions. Based on the currently accepted value of 15 points = 30U, the fair value of 1 point is around 2U. If the points exceed 2U, they can be redeemed.
For example: if 30 points are deducted in the first minute, that means it's more cost-effective if it's above 60U; in the second minute, it's 58U, and so on.
Additionally, this model does not decrease points, which means that if you do not meet the threshold, you will directly lose the opportunity to redeem.