I believe I have found a bug - I'm using the 64-bit version of RIOT and when loading large images, RIOT crashes after loading ~5% of the image. Here is a link to a test image here:
https://drive.google.com/file/d/1GRpIUYS4GIuV4La0SRxf8pprtM-L9VLE/view?usp=sharing
Thanks so much for this amazing software! I do realize this size image does not reflect what most people would be doing and is likely a fringe case, but figured it was worth reporting :)
-Dan