Some thoughts about how to munchkin tulpas:

1. If domain experts say that the obvious ways to exploit having a tulpa fail, they are probably right. That means I'm skeptical about things such as "tulpa will remind you to do your homework ahead of time and do mental math for you".

2. The most promising idea is to exploit your interpersonal instincts: trick your brain into thinking someone is there. This has benefits for social extraverts, for people who are more productive when working in groups, or for people susceptible to peer pressure (maybe you'd be uncomfortable picking your nose in front of your imaginary friend).

3. But if this works, presumably there is a corresponding downside for people who enjoy being left alone to think.

4. Probably the scariest objection I've seen here is that a tulpa might make you dumber due to diverting concentration. But I'm not sure this is obviously true, in the same way that always carrying a set of weights will not make you weaker. I'm not sure this is obviously false either, and I don't see a good way to find out.