Elasticsearch terms case-insensitive performance

Question

I'm using ES 8.7 and 8.8, and considering about 2 searching scenarios:

• Indexing without lowercase normalizer and write terms query with case-insensitive is true
• Indexing with lowercase normalize and write terms query with lowercase value

I'm searching a bit in google about searching performance comparison or best practices recommendations. Also searching in ES doc https://www.elastic.co/guide/en/elasticsearch/reference/current/tune-for-search-speed.html

So i ask this question to find the better searching approach.

Thanks.