Dedicated port buckets support is confusing docs. vs. UI

I am currently not able to create any dedicated port buckets using the below steps.

Question Is this feature disabled for 4.X onwards? If yes, why does the UI still show support for Dedicated ports, am I missing something.

Create Couchbase bucket and select Advanced settings for changing the bucket port

I get an error on entering any port number as 'The port number must be greater than 1023 and less than 65536. Dedicated ports for memcached ASCII protocol are deprecated. Please see documentation for alternatives. '

Afaik the create bucket documentation shows support for Dedicated ports.

https://developer.couchbase.com/documentation/server/current/clustersetup/create-bucket.html

while https://developer.couchbase.com/documentation/server/current/security/security-pw-auth.html#topic_jzr_ct2_gv__standardport

shows 'Server-side moxi proxy is deprecated in Couchbase Server version 4.5. Start using Couchbase client SDKs or client-side moxi in your applications. '

If deprecated, can we remove the port support from the UI advanced settings for dedicated ports.