HA Setup Review

Hello Team,

I am looking for some feedback on the HA Setup that we are finalizing for
running our business critical workloads.

We are planning to follow this Setup,
https://www.pgpool.net/docs/42/en/html/example-cluster.html

- Basically a 3 node PostgreSQL Cluster, running 3 processes i.e.
PostgreSQL DB, PGPool and WatchDog.
- These 3 nodes will be distributed across 3 availability zones/data
centers for resilience and use a synchronous replication between
Primary and Stand-by.
- Synchronous option will be Any One, so that the DB availability is not
impacted if 1 Stand-by is down for even planned outage i.e. Patching of DB
or Virtual Machine.

We see a lot of benefits of this setup in terms of availability and
managing less infrastructure v/s setting up separate machines for PGPool.

However, I wanted to know if there are any Cons/Downsides of this setup and
any suggestion to improve this setup.

Any views would be highly appreciated.

Thanks & Regards,
Akshay