I have images that cross the dateline, so I store the data in EPSG:4326 in my datastore.
Under my GeoServer WMS settings I have Enable advanced projection handling and Enable continuous map wrapping turned on.
When I request the imagery in EPSG:4326, the stored projection, images look good. But when I request the imagery in EPSG:3857, the images all look pixelated.
This happens to all images, even the ones that do not cross the dateline.
Problem is that requesting images stored in EPSG:4326 with EPSG:3857 projection with advanced projection handling ruins the image resolution.