When it comes to Postgres extensions for columnar storage, I like how Citus [1] handles the more general problem of columnar tables instead of focusing just on "hypertables" which necessarily must have a time column as primary key.
I was thinking about giving it a try until I read:
“Update, delete, and foreign keys are currently unsupported on columnar tables. “
This works fine when you have partitioned tables over time, and the current partition is row-oriented, while the historic read-only partitions are columnar.