Finding that sweet spot is incredibly difficult, and requires a lot of attention and skill.
In kendo, if I make it too easy, not only the junior won’t learn much from it, but they will get frustrated and feel that they are being dismissed or looked down on. If you go too hard on someone, you are crushing their spirit and demoralising them, and they don’t get the opportunity to learn or improve. The problem is that such environments tend to be festered in some dojo, so if you see that, best to look for another group.
The point of hikitate geiko is to give your partner both a boost in confidence and engagement, giving them opportunities to attack you, but if they don’t immediately capitalise on them, move on.
As for applying it outside the dojo, I think you have to want to share your enthusiasm about something, and when you get them hyped about it like you, it’s an awesome feeling. When you give them the confidence to try something, or ask a question, they are trusting you and it’s great. I also love seeing someone when something they have been trying to do just clicks.
I find that when learning a new skill, there is a point of psychological friction, because you feel that you suck, and just aren’t getting it. Hikitate geiko helps the junior not feel like they suck, it feels awesome and it increases morale, which makes learning both fun and effective.