Itcertainly won't hurt, and if it helps you, great! Breath control is very beneficial for people with COPD, and if this can help you controlling your breathing, all the better.
Here's a video with some basic breathing exercises for those with respiratory conditions like COPD.
Consider these just a warm- up session though. Our breathing issues usually stem from NOT getting enough of the old air OUT in time before the brain wants us to breathe in again. 🥵 These will take some practice (like it becomes second-hand) SO be prepared to do these routines at other times of the day - like walking up a flight of stairs or just carrying a jug of water around the house - from room to room,! You will then have the stamina to overcome other episodes when you feel any shortness of breath. Be well.
I can only guess that it would help @A MyCOPDTeam Member. I'm sorry I can't help you more, but I breathe the same way I always did, so never tried deep breathing. I hope someone comes up with a proper answwer for you soon.
Its best to keep moving no matter how bad your breathing is. Moving helps you breathe better.