Dear Christa Oliver,
Good day. Thank you for posting to Microsoft community.
I understand that you have a concern with the download pop up within Teams.
After thorough research and consults from my end, I'm afraid this is not feasible. I do understand your frustration and I apologize for the inconvenience you are experiencing. However, we will surely raise you concerns to our Product Team and hopefully this can be included in the future updates.
You can as well provide feedback to Microsoft by clicking on (More options ... >Help >Give Feedback) in the top right corner of Teams and submit this suggestion. You can also create a new entry in the official feedback forum Microsoft Teams · Community. Microsoft regularly reviews user feedback to improve their products.
Your kind understanding is highly appreciated.
Best Regards,
Ashraf.