That's a 4x minification, which should work with a linear filter. Could you maybe modify one of the samples to show the issue? Using our example assets, I couldn't reproduce jagged edges with linear filtering (it will get a bit blurry though, which is sadly something that we can not fix, it's how texture sampling works). Exporting the texture atlases for various densities and loading the atlas with the best fit for the screen is the option many people choose to deal with this issue. Might or might not be feasible in your case.