What happened with this? Did the guy ever post a video or anything. I was having the same discussion earlier on, It was a technical interest as didn't feel like installing twrp so i unlocked the bootloader, rooted with kind root and then installed supersu and it was persistent.
I was told that the Turbo checks the whole system directory on bootup, It had been a while since i messed with android rooting, but that is accurate.
The key part is you unlocked the bootloader.
Thus, you can write to the system, so the SuperSu was permanent (persistent). Kingroot will mess up your system, or has messed up other people's systems. SuperSu is better... but you replaced Kingroot with SuperSu.
Again, you unlocked your bootloader... so it could all be done.
TWRP, however, is great. If only for the "time machine" aspect. "I wish I could go back to when my phone was working well, before I messed it up...." Oh, you can.

You just restore the TWRP backup you made! I make a backup almost every day. Occasionally, I am REALLY glad I did so!