Rate Limiting Advanced plugin showing WARN in logs when `sync_rate` set between 0 and 1

When configuring the Rate Limiting Advanced plugin with a sync_rate value between 0 and 1 you see WARN messages in the logs like the following:

2023/04/19 14:25:09 [warn] 37258#0: *6 [kong] handler.lua:231 Config option 'sync_rate' 0.5 is between 0 and 1; a config update is recommended, context: ngx.timer

As per the documentation, the minimum acceptable value for sync_rate is 0.02 seconds (20ms), why is this log entry seen?

While you can set this sync_rate value as low as 0.02 seconds, to allow for a window_size as small as 1 second, the minimum recommended value would be 1 second for the sync_rate parameter. Reducing the sync rate below 1 second increases the load on both Kong and the Redis instance backing the rate limit counters, and can lead to Kong being blocked while waiting for a response from Redis. Should you wish to use a sync_rate below 1 second you will need to ensure that your Kong and Redis instances have sufficient resources available to cope with this additional load.