This is my very first build using a KissFC and it forced me to unlearn a lot of what I already knew and re-learn some basic things using "KISS Logic"

Setting up a Kiss flight control board is a lot like setting up any conventional Betaflight/Cleanflight/Multiwii based flight board. Except Kiss has changed the motor layout which is not a very difficult burden to overcome. However Kiss chose to put two of the signal pads on the bottom of the flight board, and two on top. So you will need to solder to both sides of the flight board and that can make routing signal wires a pain. The only other gripe I have about the Kiss FC hardware is the boot button. It is small and fragile and when pressing it there is not a very good 'feel' for when you have the button active. Pressing too hard will destroy the button, and i have heard from several pilots who have told me their boot buttons have ripped off their KissFC boards.

The biggest difference between your conventional Betaflight/Cleanflight builds & a KissFC build is the firmware and how you upgrade & configure it. IF you are lucky enough to purchase a KissFC that is loaded with current firmware, then you are in luck and you are just about ready to fly! If you have old Kiss firmware on your flight board it is recommended you upgrade firmware to take advantage of all the latest features. And this can be a headache, especially if your PC is already setup to flash modern betaflight boards. This is because of the STM32 bootloader which that our flight control boards use. The KissFC board requires a different PC Driver than Betaflight hardware. If your computer already has drivers for existing betaflight flight boards, these drivers will need to be removed before the KissFC bootloader drivers will install.
Once you get the KissFC Bootloader drivers installed you can then use a 3rd party program to load the firmware and flash it. It is not done using the KissFC configurator, and its not very easy to find the latest firmware. If you are used to the simple flashing methods betaflight & cleanflight use... you can forget all about that here. Also make absolutely sure you are using the correct KissFC firmware with the correct KissFC configurator. I made the mistake of using an outdated configurator GUI with my KissFC board, and apparently the GUI set my boards orientation to 128 degrees offset by default. Without any option to correct it. This resulted in a unflyable quadcopter that destroyed quite a few props before I realized I needed a new version GUI to fix this. Once solved, the aircraft flew (pretty damn good).

One more silly detail that pissed me off was the lack of pass-thru support for BLHeli esc's. If you are using BLHeli ESC's, make sure you flash the firmware and set the motor direction before you solder the signal wires to your Kiss board. Because there is absolutely no way to configure a BLHeli ESC using a KissFC board and if you forget to set motor orientation, you are forced to de-solder the ESC signal wires and then somehow rig them to an old Betaflight board or ESC programmer to get them setup (ask me how I know...)

Anyhow, after all was said and done, 4 hours after my build was completed I finally had my KissFC updated, configured and ready to fly. As you can see in the pictures, its a heavy pig with a 4S & Yi Camera at 557 grams. And you can feel all its inertia in the air. I might switch to a more aggressive prop and see how well it does.