Agree we need to have PNG export, already on my todo list! Until then it’s best to export as BMP and convert to PNG or another desired format in a separate application. I use IrfanView on Windows, GraphicConverter on Mac for those kinds of tasks. Not so sure about wanting JPG support since it adds compression artifacts every time you edit & save. Of course it’s always best to work from source images stored in a lossless format (PSD, PNG, OpenEXR, etc.).