Manually VACUUM bloated tables once `hot_standby_feedback` is on on postgresql?
If you have hot_standby_feedback = on, a manual VACUUM won't delete the dead row versions if there is a long running query on the standby.

The only way to do that would be to set old_snapshot_threshold to a value different from the default value. Then VACUUM (and autovacuum) will remove dead tuples even if an old transaction might still need them. Note that that would defy the purpose of hot_standby_feedback, as then the long running query might receive a snapshot too old error.