Not 100% sure what you mean by flipping over (fail?) but at least in CRDB you can of course do cross shard transactions. They wont be as fast as a transaction t

Not 100% sure what you mean by flipping over (fail?) but at least in CRDB you can of course do cross shard transactions. They wont be as fast as a transaction that can be completely handled by a single leader but it works fine and is transparent to the client.