Unfortunately no word on "Thinking Mini" getting fixed.

Before GPT-5 was released it used to be a perfect compromise between a "dumb" non-Thinking model and a SLOW Thinking model. However, something went badly wrong within the GPT-5 release cycle, and today it is exactly the same speed (or SLOWER) than their Thinking model even with Extended Thinking enabled, making it completely pointless.

In essence Thinking Mini exists because it is faster than Thinking, but smarter than non-Thinking, but it is dumber than full-Thinking while not being faster.