While working on improving the manifest, there are a few additional pieces of information that could be added which I didn't do myself:
[ ] Icons with purposes. An icon can have three purposes: monochrome, maskable, and any. There is currently an any icon, but no monochrome or maskable icon.
[ ] Language and text direction. I don't know if Etesync's pwa has been localized, but this should be filled out.
While working on improving the manifest, there are a few additional pieces of information that could be added which I didn't do myself:
monochrome,maskable, andany. There is currently ananyicon, but nomonochromeormaskableicon.I'm sure there's other improvements which could be added, but I'm just listing the ones I found.