Yes it’ll need to be soft silicone, and there’s very little movement at all, sure periodically I would push the receiver in all the way just be sure it was sitting how I wanted, but it definitely didn’t make any difference to me because it’s just mm in movement.
Yes, this is correct. When it comes to , the embedded molds can only be used with hearing aids that share the same receiver–sister brands included. So for example the unitron venture can be swapped onto the phonak lumity but not the phonak infinio which uses a new receiver. However, the software won’t necessarily detect across manufacturers, so for example the phonak software may not pick up the unitron venting code.
The friction fit and collar fit are both more flexible but it kind of just depends on what fits with trial and error so you can’t count on it. Friction fit is often more forgiving, but still technically made for a specific receiver.