I imagine that the 'risk budget' would be divided up somehow. So a company can decide to use its risk budget on 10 small studies (potentially of slightly different treatments) or one large study. They can mix-n-match and end one study early to reallocate the risk to another study to accelerate it, etc. Governments could allocate risk budgets to bio-tech companies or divide it per disease etc. The smaller initial risk budget of each smaller study decreases the chance of type I error, and the two effects could be designed to cancel.
> blinding
This approach doesn't prevent blinding. You're right that it makes it more complex. You could imagine a computer system (or independant human) that takes as input all the study results (ie. observations seen so far per patient), unblinds them, does predetermined statistical analysis, and outputs a number of new patients that may join the study today. That number could have a small amount of noise added to prevent "patient number 27 got a headache, and our patient limit fell, therefore patient 27 must be part of the treatment group".
> speed of enrollment of patients is limited by logistics
For the diseases that have the most human impact, this isn't the case. 50,000 people per day die of heart disease. I don't think any study will struggle to find a few hundred willing participants for a trial. For a disease with very few patients, the proposed scheme doesn't help, but also doesn't hurt.