ClickHouse: `staging-optimized` et engine `Replicated` ?

[ghilesmeddour]

ClickHouseClient._verify_database_supports_exchange() accepts only the Atomic and Shared database engines. My managed ClickHouse (v25.3.14) creates databases with the Replicated engine, so staging-optimized is rejected there.

My understanding is that Replicated is built on top of Atomic and also supports EXCHANGE TABLES. It does work when I try it by hand:

CREATE TABLE db.a (x Int8) ENGINE = MergeTree ORDER BY x;
CREATE TABLE db.b (x Int8) ENGINE = MergeTree ORDER BY x;
EXCHANGE TABLES db.a AND db.b;  -- works

Am I missing a reason why Replicated is excluded (some edge case with replicated DDL, cloud variants, older ClickHouse versions...)? If not, would you accept adding it to the allowed engines?

Workaround

Meanwhile I bypass the probe like this, and loads run fine (atomic swaps, readers never see empty tables):

ClickHouseClient._verify_database_supports_exchange = lambda self: None

Is this safe to keep in production, or is there a subtlety that makes the guard stricter on purpose?