What's out there with a better client device sync option? This is something I've been looking for for a few PWAs that need to operate on bad/no network, and mo

What's out there with a better client device sync option? This is something I've been looking for for a few PWAs that need to operate on bad/no network, and most other solutions are build your own entire sync setup, or magic-in-a-box you can't tune. With Couch/pouch, I can sync with a filter/several filters to make sure the subset of data I need is on the device.