Issue with WriteableBitmapEx.Blit API

Apr 26 at 5:07 AM
We are using WriteableBitmapEx library (version - 1.5.0).
From this library, Blit API is used to merge source writeablebitmap to the destination writeablebitmap destination.
This Blit() API is taking 60-100 seconds to execute, which is resulting very slow performance.

Code snippet for reference :
Rect srcRect = new Rect(0, 0, bitmap.PixelWidth, bitmap.PixelHeight);
Rect destRect = new Rect((frame.PixelWidth - bitmap.PixelWidth) / 2, (frame.PixelHeight - bitmap.PixelHeight) / 2, bitmap.PixelWidth, bitmap.PixelHeight);
frame.Blit(destRect, bitmap, srcRect, Windows.UI.Xaml.Media.Imaging.WriteableBitmapExtensions.BlendMode.Mask); //where frame and bitmap is writeablebitmap object.

Observations:
Issue is observed on Phone only.
If we run the app in debug mode, API takes around 5 seconds.
If we run the app in release mode, API takes around 60 to 100 seconds. Sometime more than this.

Expectations:
We are expecting your suggestions on this for an alternate solution or any modifications to be made to correct this API work.
Coordinator
Apr 26 at 5:18 AM
First of all think about how you phrase your expectations for a free open source project where we as contributors put our free time for free into it to make a product that can be used commercially without any royalties.

What you observe is likely a side effect of .NET Native since it's not observed in Debug mode. The NET Native Team has a fix for this that is available in a preview build. Nothing we can do.
Apr 28 at 12:26 PM
Thanks for your valuable timely response on this.
We appreciate your valuable time & hard work on this.
Thanks a lot.

Can you please confirm the NET Framework version I can pick from -
https://www.microsoft.com/en-us/download/details.aspx?id=51625