Hi Erel,
Because I use a TouchImageView to display the large bitmaps, I have explicitly turned hardware acceleration off through the manifest (SetApplicationAttribute(android:hardwareAccelerated,"false")).
So my app really shouldn't be using OpenGL in 2.7.
The fact that I can use 3000x3000px bitmaps in B4A 2.52, proves the fact that OpenGL is not active in my app.
Does the downsampling function simply downsample every bitmap larger than 2048x2048px, regardless whether hardware acceleration is turned on or off?