"However, the title of the thread states that you can improve only with a robot. Of course, you can improve, but not to the scale of either playing with other people or coaching"
Careful, we are in agreement but most writers on here use the language imprecisely. The ones who do tend to be the ones that top the monthly chart for contributions.
In this case, the op's 2nd para asked for coaching.
He did not use the word, coaching. But asked for advice on drills which is in effect is asking for coaching. That's why I spoke about solo training.
There's a book by an US player who spoke about how he trained himself to get to +2000 rating. I can't remember his name sadly.
Put another way.
1 - can a player improve by using only a robot?
Answer, yes, as it is table time.
2 - can a player improve by employing the services of a coach?
Answer, yes, as it is table time
3 - can a player improve by simply playing with others?
Answer - yes, as it is table time
4 - can a player improve by not having any table time?
Answer - no