What device do you use to do your ESC flashing?
In the old days (just a few years ago) ESCs "all" had Atmel processors. There was stock ESC firmware and there was SimonK firmware. You could make your own flashing clip to connect to the circuit board flashing pads or hand solder each ESC, but each brand needed a different clip. The solution was an adapter that connects directly to the processor. You still had to remove or cut the heat shrink tubing though.
Then there came additionally Silabs processors and yet a different kind of circuit board clip. Neither the circuit board clip nor the firmware are compatible with Atmel. BLHeli firmware came about to give us good firmware on Silabs processors. Then BLHeli firmware made a version for Atmel processors.
Now days by default these two firmwares have bootloaders that allow you to flash new firmware
through the servo / signal wires so you don't need to cut off the heat shrink any more.
One setting that is important to us is that the ESC needs to use active braking to slow down the props quickly. This gives quicker response and more stable flight. For instance, you can run higher PIDs and falling through your own downwash is more stable. This is called COMP_PWM (+MOTOR_BRAKE?) in SimonK and "Light Damping" in BLHeli.
To make a change in settings, with SimonK, you make a simple change to a source code configuration file and so you build and flash a different version of firmware. With BLHeli, you change settings stored in the ESC without changing firmware. There isn't much difference for the end user since both require using the servo/signal wire be connected through a dongle to your PC.
In addition, you can cut heat shrink and add another servo connector to use for flashing.
To make matters more confusing, you can actually run this firmware with that bootloader. IIRC the SimonK bootloader allows flashing new firmware (including BLHeli), but the BLHeli only allows settings changes to BLHeli.
To add another twist, modern Flight Controller firmwares have a flashing mode that allows you to make changes to your ESCs without disconnecting them from the FC. IIRC, the next LP firmware will have this? And some other firmwares (BetaFlight?) already have this.
So buy ESCs that already have a modern version of SimonK or BLHeli firmware. Then all you need is a SimonK or BLHeli USB dongle to do your flashing.
For dongles, I have two small, cheap Arduinos, one with SimonK flashing code in it and the other with BLHeli flashing code in it.
BLHeliSuite is one of the programs you can use to change settings or flash firmware.
If you think that reading this was confusing, just imagine what we went through to find all this stuff out and learn to use it.
I think its just another little easy thing to fix and it turn out it everything is a whole huge deal that takes me days weeks to do research , try to fix it, more research, swearing off YouTube. And finally some how by the grace of god everything falls into order and click the right sequence and it works and the heaven opens and the angles sing.
That sounds about right. To some extent or other, we all beat our heads against that wall.
My head is just flatter than yours since I have been beating the wall with it longer.