Did you want to use OneShot125 together with a 1kHz update rate?
This might cause problems with BLHeli ESCs as BLHeli also supports 1,2,4,8, and 12kHz 0-100% input signals, and has a automatic detection of all the input signals.
And a OneShot125 Signal with a update rate close to 1kHz or higher could be detected as a PWM Signal.
I did my Tests with a special version of BLHeli 13.2 where PWM detection was disabled. OneShot125 seems to work fine with 666Hz and 1kHz, but a OneShot125 Signal with 2kHz update rate was also not detected by the ESC, at least they didn't arm on this signal.
More details about this can be found there: https://github.com/bitdump/BLHeli/issues/55
I also want to do further tests with different signal type with the standard BLHeli 13.2.
The ESC are already flashed back to normal 13.2. They also seem to arm, while still having OneShot125 with 1kHz update rate on the Quanton (props removed). But i don't know if it is detected as OneShot125 or as 1kHz PWM.
On my Quanton i have about 32% CPU Load with 1kHz gyro rate, with Autotune, S.Port Tememetry and Battery as additional modules.