Audible sync on apple watch still painful and unreliable

Has anyone found a reliable recipe for getting this to work? This has been awful for years.

This morning (after updating to ios14 and watchOS 7) I needed to sync a book.

The phone and watch (V3) are next to each other, fully charged, bluetooth on, both on the same wifi, yadda yadda.

The book "prepared" OK in the phone app, started syncing and is so often the case - got stuck and the estimated time remaining starts to climb through the hundreds of minutes.

In an act of desperation I deleted and re-installed the watch app and now it's "roaring" away with an ETA of 35mins.

Following recommendations I've seen elsewhere I turned off Bluetooth on the watch forcing it to use WIFI to sync and now the speed has doubled.

But this process is madness. Anyone found a better way?