Rendering is slower by repeated API request than using UI on loop mode

It appears that if I run a workflow with the checkbox ticked to loop it, each iteration will start much faster. If I repeat the same workflow through API calls instead, it seems that there are delays.

I noticed that it immediately teleported to ksampler instantly when I started a job, i.e. it goes through all the nodes before in a flash and immediately starts displaying a progress bar. If I send the same workflow again and again through the API, there is some delay before we get to ksampler it seems. I reckon the UI has some optimization where node results are cached.

I will return with hard numbers soon, just wanted to tag the problem in case it's already known or someone else wants to comment.