Let us explore the list of available (still can be purchased in most of the stores) betaflight-native FCs that can also be flashed with PX4.
MAMBA F405 series
GSF405A 1S-2S AIO
GOKU GN405 series
Great info! a couple of questions here, well actually just one at the moment.
As for the diatone FC, where can you integrate i2c’s like GPS, radio modems…?
The one that is supported by ther master branch is explored by @taileron here https://discuss.px4.io/t/px4-1-12-on-scorpion-80-hd-whoop-w-mamba-f405-mini-mk2
It seems like there is no direct I2C pad available for wiring but maybe can follow how he did to the UART4 by direct soldering to the MCU pins?
I2C are TX3 = SCL ; RX3 = SDA (2k2 pullups needed)
UART6 RX6 and TX6 can be used directly for GPS
UART4 TX4 (PA00) is the LED pin (for telem radio)
RX4 isn´t offered so this has to be soldered directly to PA01 of the F405
In most cases starting Betaflight on time (before PX4 flashing) and carefully read the dumped cli chapter resources gives information about the pinouts.