Only been wearing aids for less than a year, and it’s been more than ten since I last flew (Glasiar RG) so I haven’t tried aids inside an aviation headset. However, I do wear them inside Quiet Rider muffs Quiet Ride Ear Muffs Helmet Speaker Installation | Quiet Ride Ear Muffs when motorcycle riding. The muffs are very similar to an aviation headset except that instead of using a headband spring to make the seal, you inflate bladders to clamp the cups to your head. I have speakers inside the muffs, a boom mike, and an intercom that provides connectivity.
The main reason I wear the aids inside the muffs is to avoid having to put the aids on and off. I’ve experimented and tried different schemes. Mostly I’ve muted the aids while riding. Lately I’ve left them turned on but at a couple notches below the default volume level. One issue on the bike that you won’t have in a plane - I can’t reach the buttons on the aids while riding, so if I need to make changes I have to use the app, which is a pain with gloves on even though I have the phone mounted where it’s easily reachable. Most of the times I want to make adjustments are because I inadvertently hit a button on the aid when putting on the helmet, or when putting on glasses inside the helmet.
There’s little benefit to having the aids on while riding - slightly better clarity when listening to music or talking on the phone. Also somewhat better when stopped and someone’s talking to me.
I’ve also been wearing the aids inside an open face helmet without the muffs while riding an ATV. That gives me phone connectivity plus a big improvement when someone’s talking to me with my helmet on.