I notice that WMS layers are failing to load on some of the demos, for example here: https://ships.lib.virginia.edu/neatline/show/iliad-book-2
Following the example given at https://gist.github.com/waynegraham/c7d9ae298e0fe977f0ea I created a /neatline/layers/wms.json definition file, linking to wms resources on three different servers. None of them could be displayed.
It appears that the wrong zoom level is being requested by my Neatline Exhibit for these layers, consistently several levels below the coincident requests for OpenLayers base map tiles. I suspect that the x & y coordinates being requested are also wrong.