Something to share here.
My FE bought in April.
After an update in May, ghost touches did improve, but still have minor issue.
Not affecting my daily use though.
Can't say the same for others on gaming.
Experimented with slightly different tests from the 2-finger fast swiping.
Just did simultaneous finger taps to simulate multi-touch.
From the above images, you will see the erratic touches/swipes only appear when only doing the 3-finger taps.
It is not even present when doing 4 or 5-finger taps.
This is so weird.
Did the same tests on my S5, absolutely no problems at all.
Someone else should try on your sets and share.
Edit: 3-finger tap errors are more pronounced when the 3 tap positions are aligned vertically. Zero errors for me when the 3 tap postions are further apart or aligned diagonally.
. Make sure gestures are off otherwise it will influence the test.
