Hi @blixtentoo, Link below for wedge I use. In addition to wedge, we also put head of bed up on some blocks. Both of these together have helped my reflux. Honestly, the wedge alone was not enough. Now the sleeping angle is somewhere between 28-30 degrees. Those maneuvers (wedge and blocks) were an attempt by hubby to avoid purchasing an adjustable bed. That said, we do have an adjustable bed in guest room which I occasionally use for postural drainage.

It's sensible to know where the bronchiectasis is in your lungs so you can target that area with the correct PD position. Theoretically, your pulmonologist will review scan with you and point out the areas to focus on.

What I do is hoist up my hips with bent knees up on the wedge (or fully raised foot end of adjustable bed). This creates a slope for me when I lie down. Right side then left side. I do this after upright autogenic drainage (AD app) and lying down flat. It takes a lot of time especially in the morning. It's very much a drag and my hope is that some of the future medications will either 1) decrease the mucus and/or 2) help the mucus come up in less time. Hope springs eternal!

I've read that some also use inversion tables for postural drainage. Maybe that would hasten things? Some people use folded blankets on the floor to create a slope. It takes some fiddling to figure out what works for you. It seems to me that a simple collapsible cot like bed could be designed with a downward slope.
https://relaxtheback.com/products/contoursleep-side-sleeper-bed-wedge?_pos=2&_sid=3bb772ad3&_ss=blixtentoo