Outline+ handwriting problem

I choose Outline mainly because I can do handwritings with it to Onenote files, which is not supported by the free Onenote for iPad currently.

But there's a big issue about handwriting. When I use the drawing mode, everything is alright, but in the handwriting mode, the experience is very awful. How do I put this, when I wrote, the "ink marks" shows up very slow, looks like it got stuck somehow. For example, when I write "a", I can't see a shows up immediately, only a second later or so did it appears. So when I write, I can't get the instant feedback without which I can say I can hardly write. It's a big deal.

I've been using other handwriting apps at the same time, for example NotesPlus which is a way better experience.

If this can't get fixed, I very much like to get my money back. Like I said, handwriting is the crucial reason why I chose Outline.