I see it each time. API connector slows down on typing of each character itself.
What I have observed is that somehow auto-save of app is extra slow when we make edits in API connector. So, even if you are just typing name of API call, it seems like it is making full save and writing full application to the disk each time a keystroke is being entered there. You can see a “saving…” on top of the editor each time you do anything small in API connector. So you make a keystroke, it will start saving, and will only respond after that once that “saving…” becomes “saved”.
One hack that I use is that I write the text in a notepad or something and then just paste the texts directly in API connector. It could be the JSON code that I have to write in the body or name of the API call or anything which requires entering text beyond a few characters.
That saves some time.