Cool! I used to repair laptops also years ago haha. Phones nowadays just too hard to fix without leaving tool marks for me hehe.
U mean 535 touch screen issues? I also using a 535 as 2nd phone. Have to say the touch screen issues r disappointing.
The technical preview is up liau now. They had some server errors till like 2am or something. So who's gonna install it? Hehe

That is correct. Microsoft said if W10 not showing try again later.
No slow ring for new insider users
Oh ok. That's odd my 535 almost as sensitive as my 1520. Worse is the 535 have issue tracking 2 fingers or more accurately. I found that ever since I changed how I store my 1520 only on it's back, I've had very little phantom touch issue.

Updating to W10 on the 535? That won't fix the bugs.
U just need patience bro