As a number of people here will know, and the clue is in my avatar pic, I have an activator among other things.
I regularly wear a bite plate or hawley retainers and, in fact I chose to wear full and thick removable plates for about 5 years continuously some time ago. However, generally these did not show. I got so used to them that they dont affect my speech any more and eventually it was quite difficult to speak without them on the few occasions that I tried. (I remember one day that I took them out before visiting some friends, just to see what it felt like. I found it so difficult to speak clearly without lisping and tripping over my words that I made up a quick reason for going back out to my car and slipped the plates back in again.)

Anyway, the one device which I have never worn in public is my activator. It feels great to wear but obviously it is a bit of a challenge. It holds my jaw rigid and although I can speak reasonably well with it in at home,  it is quite obviously noticable. A look of top and bottom hawleys but also a fairly obvious gap at the front for breathing and speaking (and drinking if necessary), plus the lack of jaw movement.

Anyway, today I needed to go to one of the large out-of-town DIY stores.
Due to the covid restrictions, all stores are requiring face masks so suddenly I thought of going out wearing my activator for the first time.
I put it into my pocket and set off.
Just before I arrived at the store I slipped it into my mouth and as i got out of the car I put on my face mask. There was no turning back. I knew that I may have to speak but I also knew that no one was likely to ask me to remove the mask and it was very unlikely that I would meet anyone I knew.

I picked up a few items on my list but then while I was taking a long time puzzling over the choice of some items on a display, an older assistant came up and asked if I needed any help deciding. (Probably checking me out for potential shoplifting as well!)

I answered but it was suddenly much more difficult to speak than when I wore the activator at home. In fact it was really difficult to form words because I was concentrating on what I was saying. But there was no way out. He must have thought I had a speech impediment but at least the mask covered up some of my difficulty and we exchanged the necessary bits of conversation.

Finally I needed to go to pay. There was not going to be much to say at that point so I felt fairly confident.
When I arrived at the checkout there was a couple infront of me discussing an item which they were about to buy. There were obviously uncertain weather it was the right thing.
I overheard what they were saying and I knew about the item they were buying.
Without thinking, I asked them if I could advise them and they were pleased to ask questions and get advise. I explained what they needed to know and they were happy. It was only as I continued to pay for my items that I realised that I had held that conversation wearing my activator, (and cloth mask) and had managed to speak quite clearly and sensibly, I think! Obviously there was much less of a problem because I had forgotten to be self-conscious and listen to my own speech

An interesting first venture out wearing the activator but as soon as I was back at home I went back to the bite plate and total normality.