Do you have some links I can check please ?
https://mercurycustomplugs.com
I was told this by an audiologist when I went to get some impressions made to get some in ear type ones made. He strongly advised me to get the best over ear type ones I could and I did just that. Huge thumbs up for MSA Sordin Pro with the gel cups. Sound quality excellent and they are really comfortable. For the first little bit I did on occasion tap the bottom of the right one on the stock. But I learnt to adjust the way I mounted and it hasn’t happened in years since. I have had mine around 7 years. Use every weekend and haven’t (touch wood) had any issues whatsoever.
Respectfully, the relationship between deafness and dementia is not that deafness can tend to bring on dementia, but rather that it can be one of the early symptoms of dementia
I very much doubt that they would swap. The modules look totally different from the front.
That’s what I was warned of when I went to get my moulds done
I also shoot with a friend who is having some trouble with his in ear moulded plugs dropping the digital inserts out which is an expensive way to loose a couple of hundred £££ if your not careful
had a pair around 7 or 8 years now still going strong 
