So, I've been doing these stretching exercises for about a week, and I'm glad to say it works to some extent. I've gained 1cm on my morning height, and that wasn't due to posture. Like most here, I also obsess over height measurements, so I always made sure to use the best and most exaggerated posture possible when measuring my max height. Despite that, I noticed I gained 1cm on my max height after I started doing these exercises consistently for a few days.
Here's the link.The title is clickbaity and there's no way anyone will gain 1 or 2 inches from this, unless they never noticed when they were slouching before. However, I'm sure most people here would be happy with any gains at all in height, so I decided to share it here. It might not work for everyone, but it worked, to some extent, for me.
Do them after waking up and before bed. You also don't need to do all of them.