Congrats on you newly ordered HAs!
When I got my 105dB custom molds recently, they come with vents. But my audi gave me a pair of plugs that goes into the vent but it has its own smaller hole. So I wouldn’t be too concerned about your audi choosing a vented earmold. It may just come that way by default without your audi having to specify it like that. The assumption may be that you’d just plug up the vent if it’s too big to your liking.
One thing I was told is that if I use the plug (it goes on the inside canal end), don’t cut it off too flush with the mold because it’d be virtually impossible to take it out afterward. You’d want to leave enough hanging out so you can grab and pull it out if you change your mind.
I ended up not needed to plug up my custom molds’ vent holes, however. Even though they seem to be bigger than the bass dome’s single vent on my 85dB receivers, there’s no feedback when I cup my hands over them, even though I didn’t have to run the feedback program on these custom molds at all. I did have to run the feedback program on the bass domes of my 85dB receivers, however, even though their vent hole size is smaller than my custom molds’ vent. Go figure.