postgresql11 space reuse under high delete/update rate

Hi

we are evaluating postgresql 11.1 for our productions.
Having a system with 4251 updates per second, ~1000 delete per second and ~3221 inserts per second and 1billion transaction per day.
we face a challenge where PostgreSQL does not reuse its (delete/update) space , and tables constantly increase size.
we configured aggressive Autovacuum settings to avoid the wraparound situation. also tried adding periodic execution of vacuum analyze and vaccum -
and still there is no space reuse. (only vacuum full or pg_repack release space to operating system - but this is not a reuse)

following are our vacuum settings :
autovacuum | on
vacuum_cost_limit | 6000
autovacuum_analyze_threshold | 50
autovacuum_vacuum_threshold | 50
autovacuum_vacuum_cost_delay | 5
autovacuum_max_workers | 32
autovacuum_freeze_max_age | 2000000
autovacuum_multixact_freeze_max_age | 2000000
vacuum_freeze_table_age | 20000
vacuum_multixact_freeze_table_age | 20000
vacuum_cost_page_dirty | 20
vacuum_freeze_min_age | 10000
vacuum_multixact_freeze_min_age | 10000
log_autovacuum_min_duration | 1000
autovacuum_naptime | 10
autovacuum_analyze_scale_factor | 0
autovacuum_vacuum_scale_factor | 0
vacuum_cleanup_index_scale_factor | 0
vacuum_cost_delay | 0
vacuum_defer_cleanup_age | 0
autovacuum_vacuum_cost_limit | -1
autovacuum_work_mem | -1

thanks in advance, Aliza.
This email and the information contained herein is proprietary and confidential and subject to the Amdocs Email Terms of Service, which you may review at https://www.amdocs.com/about/email-terms-of-service <https://www.amdocs.com/about/email-terms-of-service>