Kibana slow performance optimization

I have a Kibana page which takes about 7-10 seconds to load.

Benchmarking same page shows ~1s to complete the request

$ ab -n 10 "http://kibana/app/discover#/view/15a67850-6921-11ea-8308-058e42e28132"

and the exact same query to elastic takes about 1s to complete as well.

$ ab -n 20 -p same-query.json -T application/json "http://kibana:9200/logstash*/_search"

It's just 2 simple match filters within a request to logstash* index.
Taking into account benchmarking above I don't think the the issue related to Elasticsearch/Logstash but rather to Kibana itself. So my questions are:

• Is the a way to tune/optimize performance for Kibana (page loading time)?

• In case I move Kibana UI to separate instance will that give any benefits to performance? (currently it's ELK stack on the one instance 8 vcpus, 16 GiB memory)

• How can I additionally narrow down the exact reason of this slow performance?

So basically I've ended up turning these flags off (/app/management/kibana/settings)

filterEditor:suggestValues
discover:searchOnPageLoad
doc_table:highlight
visualize:enableLabs
telemetry:enabled

Other ideas I had in mind:

• adding nginx as a proxy caching all the static files (js for plugins / images)

• warmup script (periodically makes requests to predefined hot pages for Kibana to internally cache these pages) if that would work

• migrate to hosted cloud solution which might be optimized better for the loading time

StackExchange DevOps Q#12660, answer score: 3