I just installed mine. I can't say I'm overly sold on this.
This was supposed to be a drop in replacement apart from moving the jumper. This is what my 29e31s looked after installing the flyback:
https://imgur.com/a/pisqxzF
https://imgur.com/a/2BOOOKA
Crazy interference.
I suspected it was high HV causing this. After I removed a mountain of glue that was placed on top of the pot:
I turned down the pot (counter-clockwise) and the interference on bright backgrounds went away. The shaking in the test menu is still there. Also, as a cause of turning down the pot, the screen expanded a ton and the corners went super blurry.
As for the artifacts that appear on backgrounds depending on what's being displayed, if you turn down sub contrast and or HV you can mostly get rid of them. I'm not sure how much of this is a chassis issue and how much a flyback one. The Technoservice flyback definitely exacerbates it, but I have seen it with the original flyback too.