partitioned tables in high OLTP db

Hello,

I'd like to ask for your opinion and experience you might have with
partitioned tables on a production OLTP database.
We have a couple of tables reaching 1T and beyond and liked to have them
partitioned.
We built a pg14 full volume db.
To get an impression of the new performance we're executing most frequent
oltp queries
and comparing plans and execution times with the production "monolithic"
pg12 db.
For most of the queries we managed to get the optimal plans.
Execution times however increased , especially with planning time. Say from
1ms to 6ms/10ms
Typically there are joins between 3-6 partitioned (~40 partitions) tables.

That's the only thing we can examine . No load/stress tests are available.

Something else we should consider? (I saw lock contention has been noted
in the forum.)

Thank you for your time.

Regards,
Rado