Thanks for sharing your thoughts. As usual, I have considered almost all of these at one point or another. The variable flow rate, in particular, I have come really close to implementing in some of my aircraft. The donning and doffing, you will see implemented in my Starship, King Air, and TBM by pressing the tabs on the mask to inflate the quick donning function. As for the "effects", I really wish there was a good way to do this in MSFS, but I have yet to see an addon come up with a clever solution. The only options I've considered are very ham-fisted, and I wouldn't feel confident about their reception. I will keep looking for clever solutions, but for the time being, I would say that variable flow rate is the most likely of these that you might see from me. Thanks for sharing! I hope my message doesn't sound like a dismissal of any kind. The only way I know what features will be most enjoyed by the community is when you share them with me, so I am always happy to hear from you!