Update: I've come up with a possible solution using such a "buffer" database for incoming changes. Some first, simple tests are promising. I was able to add/modify/delete data on one device and it synced to another device, keeping all relationships and such in tact, even though the order of fetched batches are not always "correct". I might still hit a road block with this, but maybe I'm getting somewhere.

Once I got it working properly, I will write down what I've come up with and what I've implemented and publish it somewhere. Maybe it will help someone :)

Yep 👍 Sorry, I wasn't entirely clear about this when writing the problem also happens in a simulator and on device. I do inject the environmentObject properly in the app. Also, MiddleView (which contains the environment object) opens fine, just when you try to push InnerView, it gets stuck in an update cycle.