I just have a tip for anyone with a screen protector which has just been applied. When you first apply it, you might feel that there is a little friction on the screen.
Here is a simple solution. It worked for me and i do not feel the friction when writing.
All you need to do is grab hold of a clean rag or duster. Spray just a bit of furniture polish on it.... Like pledge or mr min. Not too much. And just wipe off the screen guard until its clean and dry.
Once done, you can use your s pen flawlessly. No friction or anything. Great when taking down notes at a rapid pace or even drawing on screen.
Let me know if it works. The polish does not damage or dull the screen guard in any way at all. I tried this with the crystal clear screen guard