BLHeli v12.0 has been released.
I installed BLHeli v12.0 on a quad with Skywalker 40A ESCs (Silabs based).
I tried to open a saved v11.2 configuration file and convert it for v12 but there was no facility and 4712's response was “why would you want to do that, configure it from the ground up”.
Turns out that the “fully damped” feature in BLHeli has been dropped… I always wondered why you would do that and my tests on a few motors revealed it worked really poorly (see BLHeli v11.2 damping evaluation).
I have come to a view that running COMP_PWM (which BLHeli calls “lightly damped”) is not worthwhile on my quads, it might improve motor responsiveness a little, but at the expense of creating regenerative battery current and that has issues in testing.
So the only config change was to turn off the beacon facility as I equip my quads with a “Discovery beeper” which makes a lot more noise, can be used selectively, and draws much less current so is available from the battery for much longer… and it doesn't go off during extended testing and configuration sessions where the bird is powered but motors not turning. To my mind, defaulting this to ON is a bit silly.
It all worked ok, I couldn't really tell the difference from v11.2… but then I don't use challenging motors. I doubt I will upgrade beyond v12.0.
I have discontinued use of BLHeli on my Atmel based ESCs, they now run SimonK so I cannot comment on v12.0 on Atmel. SimonK is more responsive, simpler and doesn't have the BLHeliSuite baggage and it works with all the motors I use. (If you have motors that challenge SimonK, they may work better on BLHeli and so it might be the solution for you.)
I do see complaints from people who have bought ESCs with SimonK bootloader installed but with the lock bits programmed to protect all of flash, and although the SimonK bootloader will load BLHeli (the bootloader ignores the lock bits), BLHeli will not run as it checks the lock bits and locks up if they are programmed… some kind of ill-conceived anti protection scheme that is easily circumvented. (Though BLHeli is unquestionably open source, BLHeliSuite is not open source even though it incorporates some open source GPL elements, so the anti protection scheme is a bit hypocritical.)
Be warned that some ESCs shipped with SimonK installed have the lock bits for flash programmed and BLHeli v12.0 is incompatible with them, they will have to be erased and reprogrammed with an ISP (or HV) programmer.