I applied the Spigen NeoFlex last night as a temporary holdover until I can get one from Bodyguardz however, I am not entirely sure what to do. I also have the Spigen Tough Armor case and from what I can tell, the edge of the NeoFlex and the edge of the case is really close so if there was any protector that was a little bigger than the NeoFlex, then the case would make it lift.
The NeoFlex is ok, but I prefer something harder - like PET plastic. Bodyguardz made those for the S7e, and the one they have for the S8+, I am not sure it is made of PET plastic. If not, then I might hold off. PET plastic is as close as you can get to glass without it being glass but it sticks to the screen at all points, not just some points like the glass ones. The NeoFlex is soft and with fingers it is okay - but when I put one of these on my Note7 last year, I had to rip it off because the self-healing properties didn't really self heal 100% when using a stylus.
Not to talk about cases - but for anyone buying a Spigen Tough Armor - if you had bought these before for the S7e, you will notice that the one for the S8+ has edges that are higher then previously - meaning that it comes up on the edge more than before. As a result, if the protector isn't case friendly, you're going to have problems - and I think you might have problems with some that are classified as case friendly as well. It is literally a perfect fit with the NeoFlex. I am interested in hearing if people are having problems with screen protectors and the Tough Armor, or if it's just in my imagination.