Previously, when it got blocked, it required meditation for several days or even hours to reopen it. Recently, with emergency measures, it can be reopened within an hour, and with a few hours of meditation per day, it can recover to some extent.

When this area gets blocked, it becomes quite critical, and consciousness becomes chaotic and hazy. However, even if seated meditation is difficult, focusing consciousness and intending to open that area can open it to some extent. At that time, I feel that if you put your palms together slightly apart in the center of your chest, like a Qigong form, it becomes easier to cultivate energy, and an aura tends to gather in the forehead. By doing so, you open the Nadis (energy channels) around the nose.

Originally, it was open, so even if it closes, it is relatively easy to open, and there is not as much difficulty as when opening it for the first time.

When I look around, surprisingly few people have this area blocked. In my case, it seems that bullying and being yelled at during childhood, and rejecting people with such a temper, caused a feeling of rejection, and that feeling of rejection may have been the cause of the blockage in the Nadis (energy channels) from the nose to the forehead.

Bullying/yelling → Contraction, rejection of people with a bad temper → Blockage of Nadis (energy channels) from the nose to the forehead.

I think that was the order. It took a surprisingly long time to resolve it, but I think it was put off because I wasn't even consciously aware that there were Nadis (energy channels) in that area.

Head relaxation → Movement begins in each part of the head → The energy channel (Nadi) from the throat (Vishuddha) to the forehead becomes stronger/thicker → Similarly, the energy channel (Nadi) from the forehead to the back of the head becomes stronger/thicker → An energy channel (Nadi) begins to form from the back of the head to the crown (Sahasrara).

I think the order is like that.

In terms of the percentage of how clearly the channels are formed, it is roughly as follows:
Throat to forehead: About 50%?
Forehead to back of head: About 30%?
Back of head to crown: About 10%?

In reality, I don't know what a completely open state feels like, so the range may be different, but the percentage is roughly like that.