Hot to decrease response time for ReadAPI?

We're using ReadAPI to read some simple labels with little information, the final JSON is about 5kb.
The uploaded JPG 100kb.
The response time varies between 0,5s (rarely) and 2s, more often around 1s.
We check result every 250ms.

Result quality is very good, but is a litlle bit slow.

Is there a way to improve the response time?
A more expensive tier with more computational resource?

We were thinking of implementing the docker version locally, but what time of computer/processor/memory would be necessary to compare with the cloud one?
Then we would have to go for a more powerful one.
Trying to understand if it is worth it to go for the docker local solution.