After a LOT of trying and digging I figured out what the problem is and the answer is... its not a problem, but a windows feature and its present on any PC, Laptop or tablet that runs it at all times, even if you`re using a mouse.
So what is it? Well, its a snapping "feature" windows has that snaps whatever youre trying to hold and drag to the cursors original location. Once you live the "deadzone" area, whatever youre trying to drag will move to your where your cursor currently
is at. I figured this out after opening Zbrush`s infos and noticing that it was in fact recognizing every touch and action I was doing with my surface pen and that not only the "lag" would happen when I was trying to sculpt, but also anywhere else on the screen,
including interacting with the UI.
If you wanna get to this conclusion yourself too, try opening your desktop on your surface and then try holding and dragging a folder around. Youll notice right away that the same thing that happens on zbrush also happens on your desktop. Your folder will stay in place even though the pointer under your tablets pen wont and then itll jump to the pointers location once it moves out of the "deadzone".
Anyways, I figured this could shine some light on this problem since now we know its not software specific, but a windows thing. Personally i imagine thats one of the things that companies like Wacom fix when they release drivers for their own tablets, but
since Zbrush is not as globaly used as software like photoshop and pixologic isn`t as big as Adobe, no driver has been done to get around it.
Sadly I dont know how to fix it yet though, but Ill post it hear if I find out.