PostgreSql .config parameter when using Osm2pgsql --append

I have already imported the OSM Planet to the database. And I want to update the database regularly. The update command I use is osm2pgsql --append -slim with 6GB cache. However, the update process is still too slow.

Hardware: 32G memory, 1.7TB SSD.

Database config:

shared_buffers = 2GB
work_mem = 1000MB
effective_io_concurrency = 2
fsync = on
synchronous_commit = off
full_page_writes = off
checkpoint_segments = 100
checkpoint_completion_target = 0.9
autovacuum = on
effective_cache_size = 4GB
maintenance_work_mem = 2GB
max_worker_process = 12

On average it took 1 hour to process 6 hours worth of new OSM updates. (Screenshot is the log printed by the script openstreetmap-tiles-update-expire. Inside the script, it calls osm2pgsql --append -slim)

I remember when bulk loading OSM Planet to the database, a lot of articles suggest modifying postgresql.conf

Such as:

fsync = off (import only!)

autovacuum = off (import only!)

Since the database is keep updating, should I change the postgresql config settings back to these import settings to increase performance?