I made this mistake some time ago and after that it has very hard for me to recover the phone (i'm not a very expert on that). NEVER, never, never format SYSTEM partition.....Because it may get misinterpreted, by format system/data you mean to format data, right? Cuz formating the system partion could probably cause HUGE issues.
Doesn't help at all. Always back to 12.0.15 stable android 10, this is the best as long as android 11 and several versions of 12.1 or 12.5 releasedIf you have not already done so, clearing Dalvik and cache, and also deleting /data/system/package_cache folder has helped some with lag.
I don't mean to be pedantic, but what you're referring to is the "persist" partition - you are correct, though; messing with this will break your Widevine L1 and it's nearly impossible to get back. This partition also contains all your sensor information (accelerometer, gyroscope, proximity, etc.)can`t really help you but any solution containing the word "persistant" should be avoided.
As long as you follow above you might be helped in the future.
Last week I waited before I downloaded, and the speed was quite good. WIth limited bandwidth from the servers, and everyone rushing to get their new ROMs, there is always a lot of congestion to start with. So if you're not in too much of a hurry, it is better to wait - it will be faster, and there will be no drops.Is it only me or the download server is really slow? I tried both sourceforge and afh. My internet is fast enough to watch hd youtube video without buffering