I mean about all thing, for example, I select a brush and then I just want to start drawing and if I start to move the stylus across the screen it does not react like in other programs, that is, I first have to click on the screen to disappear the brush menu and then just draw and this is present in all options of the program, for example, if you try to do it in a procreate(take this app as a performance standard), then there it happens instantly, without these debilitating delays. And this happens throughout the program, this delay is actually annoying especially in products from Apple it's unforgivable, sorry for my aggressive tone guys. Wish you can fix that.
Forgot said about my spec: iPad pro 12 first gen, iOS 11.
Good luck.