If the UNLOGGED tables are unavailable on replicas, you’re now putting read loads back on your primary which sounds like it defeats the point of having replicas to begin with?
The last claim: “…[with] better persistence than traditional caching services…” seems like a weird claim to make if these tables get truncated on DB crashes. Redis with AOT seems far more robust.
There’s a few things here I’m a bit… eh on: