I have done that 4 times, twice after 9.6.3 and twice after 9.6.4
It did NOTHING. my usage has gone down heavily still the problem is there.
After charging to 100%, even if nothing is on including mobile data, WiFi, battery drains fast and within 1-2 hours it comes to 90-91%. Then it stabilizes.
I have mentioned this including logs etc. No response from the tech team so far.