Max PWM frequency

[kepten]

about KC868-D16, it's output 0-10v

That's the problem  . It is not dimming the 12V just outputting some control PWM signal in the 0-10V range which another product would need to receive. That "another product" is the question then. What could handle 20kHz and a couple of Amperes of load, do you have any concrete examples?
Dimmable LED PSUs are expensive and I'd need one for each output of which I have around 20 so it's not feasible. The LED drivers (without PSU) which I could find are only capable of handling ~1.5kHz max, which is not 20kHz which I'd need so they are not a solution either.

[admin]

Do you think if KC868-AP remove the PCA9685 , use ESP32 pins connect to driver IC directly will be ok?
how many channel you want? maybe ESP32-S3 not have enough GPIOs for PWM output.

[kepten]

Do you think if KC868-AP remove the PCA9685 , use ESP32 pins connect to driver IC directly will be ok?
how many channel you want? maybe ESP32-S3 not have enough GPIOs for PWM output.

Yes, removing the PCA9685 for the outputs and letting the ESP32 output the PWM signal which is then "amplified" by a MOSFET driver IC connected to a beefier, low Rds_ON MOSFET should work since this is exactly my current setup. If the driver IC and MOSFETs are properly chosen, it should not get warmer than 30-35 °C so no heatsink is necessary.
I created the PCB I currently use myself. It works but I'm looking for a more "industrial-grade" (e.g. din rail mountable) solution or at least something which was designed by people who are PCB experts and not hobbyists like me.  
I think 10 or 16 channels per board should be fine. If someone needs more output (like me), they could buy multiple boards.

Here (https://quinled.info/quinled-an-penta-di...are-guide/) is the only board I could find which on paper should satisfy my needs but it is not available as a pre-made board. On the page I linked there is schematics and concrete component list (orderable from LCSC) which might help if you decide to design a new Kincony board for filling this market gap.

[admin]

which MOSFET driver IC model you think is ok?

[kepten]

which MOSFET driver IC model you think is ok?

I use this driver IC and this MOSFET. The Quinled board uses this driver IC and this MOSFET. I have no experience with the latter but should be also fine.