Ok, I went ahead and got me an ESC. It claims to have 35A and was only 10€ delivered out of Germany (where I live). From China in packs of 4 these are even cheaper. https://de.aliexpress.com/item/32856381318.html?spm=a2g0x.12057483.0.0.666256a9C2bgRM
The Board has an stm32 MCU and I believe it routes 6 pins to the FETs via this fortior chip as drivers. Would that mean it is possible to run in 6PWM mode? This board is 3 layers I believe, at least I’m not able to follow the traces.
As you probably already realized I am not an expert with this 
I managed to “solder” some wires to the exposed programming pads, but they are indeed tiny. Soldering to the pins of the 5x5mm UFQFPN32 is impossible to me, so I will be stuck with the swdio, swclk and the PWM input pin (still have to figure out to which input it connects).
This means to control the motor I would be able to do software I2C, step/dir or anything like that only. There are versions of blheli_32 boards with what they call telemetry output via dedicated pins. Its probably better to go with those for any real use as it probably exposes some kind of serial interface.
For me this is a theoretical thing anyways as I don’t even have a use case, but want to play around with electronics again after a longer break.
However, now I am facing a problem I think @Jan_Donker is referrring to: The chip is protected. (see screenshot)
Is it still possible to uplaod anything to it? Are there fuses I can change or should I just try to compile something and download it?
EDIT: I found a blheli_32 board in platformio:
