fwiw, CREATE [TEMPORARY] TABLE AS SELECT can be problematic in MySQL even without Galera. It is outright disallowed if MySQL 5.6+ Global Transaction ID (GTID) is enabled, for example. The issue is that it's combining DDL and DML in a single statement/transaction, but DDL is still not yet inherently transactional in MySQL.

The work-around is to just to use two statements, CREATE TABLE (or possibly CREATE TABLE LIKE) and then a separate INSERT...SELECT.

That all said, yes, Galera should ideally handle this gracefully instead of ever deadlocking. But I don't have enough Galera experience to comment on that aspect.