Do notifications show over a FaceTime call

For all the experience I have, calling my family in multiple IDs, the person only knows the ID that they already have, and FaceTime has no options to automatically reveal the other IDs that person uses.

I wanted to enable some automatic thing like this for myself, because I have 4 different cell numbers and 3 e-mails with FaceTime. Still have not found how to do it.

So for you, the answer is "no, they still only know about the ID they used".

I'm not sure there is a standard way. It certainly isn't easy to find by using the Contacts or the Facetime app. But, it can be done:

1. Send a text message to the specific number you want to Facetime call.
2. Open the conversation thread.
3. Click "Contact" in the top right.
4. Click the symbol for calling.
5. Choose "FaceTime Audio".