Well, I tried it, and unfortunately I can't say that it was good for overclocking (at least for my hardware). I decided to switch to my previous one until next release of BOS.
You were mislead. The point of bOS is NOT overclocking, but actually UNDERclocking.
It is about achieving the best efficiency ratio, the maximum hash per watt you can achieve. Overclocking actually does the opposite (unless your electricity is free and unlimited), which in the end means you earn less money.
Worry about lowering those voltages and speeds, and keep the hash going. There is no automation, every single hashboard needs to be carefully tested and measured to find out where its best efficiency lies. Again the lowest watt per hash you can manage is different per BOARD.
And because there are no "automated safety features", you are better of NOT doing overclocking, anyway. You can easily burn your miners using wrong configuration settings. Do not follow those that tell you overclock is good, it isn't. Best efficiency always wins, and with S9s, that is almost always by underclocking.
You need to measure power consumption and test speeds/voltages by yourself, PER board. No hand holding, if you want to make proper use of bOS. It is not "install and forget" firmware, you have to earn your efficiency which in the end will make your miners more profitable and longer lasting.