Portable fan driver module

Design Rationale:
Originally, I wanted to utilize an idle fan to create a miniature version for easy assembly with fan blades. However, considering the potential for battery drain with an embedded battery, I opted for a Type-C input for power, compatible with power banks. Two versions were designed: a simplified version without an MCU and requiring no programming, and an optimized version using an Air001 to generate PWM for driving and adding other peripheral functions, allowing for more comprehensive functionality. Both versions support adjustable fan speed and can be used for tasks like welding smoke extraction, cooling in summer, etc. The Air001 version can power LEDs for illumination or UV curing (the UV LEDs are external and not yet implemented; only control code is added). The
simplified version works as follows:
First, a 5V voltage is connected and boosted to 12V via an MT3608 to power the fan. Simultaneously, the 5V voltage powers a GP9101. A variable resistor is used to change the PWM duty cycle of the GP9101, thus adjusting the fan speed. The fan is a 4-wire PWM fan,
version Air001.
The 5V is stepped down to 3.3V via an LDO to power the Air001, and simultaneously boosted to 12V to power the fan. The Air001 emits PWM to control the fan speed. Each button press increases the duty cycle by 20%,
returning it to 0% after reaching 100%. The indicator light brightness changes with the duty cycle to indicate fan speed. A WST3400 is used to control the external UV lamp (which is not soldered).
Attached are demonstration videos for both versions, as well as the code for the Air001 version.
Several problems were encountered during the construction process. It was discovered that the 100k resistor in the package purchased online was incorrect; it was labeled 100k but was actually 100R, which could not be used for proper voltage boosting. A 0603-sized resistor was found and reinstalled. However, the GP9101 chip in the simplified version was faulty and could not adjust the speed. After purchasing a new one, it finally worked. However, due to repeated soldering and my desire for simplicity, the soldering time on the heating plate was too long. Several potentiometers were damaged (melted). There was also another issue: initially, I didn't understand fan rotation direction control and mistakenly thought adjusting the PWM duty cycle to be complementary would suffice. In reality, a 4-wire PWM fan cannot easily change direction; only a 2-wire fan can change direction by swapping VCC and GND. Therefore, the initial direction-changing function was removed from the project. I didn't even solder the direction-switching switch on my board.
The Air version also encountered many difficulties.
After soldering, I discovered the circuit was drawn incorrectly, and the main controller lacked 3.3V power, requiring jumper wires to solve the problem (the schematic and PCB have been corrected in the project). With the hardware issues resolved, the software was also stuck for a long time. I studied the PWM code extensively and felt it was correct. The only problem was the LEDs not lighting up (during development, I used LED brightness as a duty cycle indicator). After investigation, I found that the LEDs wouldn't light up when the brake was activated. Therefore, I disabled the brake function. The PWM successfully drove the fan. I also added a breathing light effect, etc., all in the code project. 
[Image of the simplified version] [
 
Image of the Air001 version]