I have a question, should I ask for re-indexing in Search Console with every slightest change?
Because I do not know if it is profitable when, for example, I add some additional text, a new category, a blog post.
Yes I did all these things.
I have one more question, such updates happen immediately or do you have to wait a while?
Your map will update automatically when you publish. It might take a little while to reflect this in Search console but mine seems to update within the day.
Now, I can’t answer what google does after that.