There are two ways to import png data into an Notes 8.x document. One is to directly import a png, and the other is to import png images as part of an HTML. Importing pngs as an HTML is currently not supported. So this is not an issue here.
Importing a png directly is partially supported on the current Notes 801 clients by converting it to jpeg. But animation and transparency of png are lost because jpeg doesn't have the features. We can fully support png images on an HTML on 8.5, but then we will lose backward compatibility.
Development is giving me 2 options. Which do you prefer:
1. Always convert png to jpeg. This has maximum backwards compatibility.
2. On Notes 8.5 clients, Render as a png data. Animation and transparency are supported.
The image is saved/loaded as a png data.
However, on older clients, A png image in a document becomes complete blank with a small red x, because the old clients don't know the image format.