I open the app on my test machine and click Open so the quarantine flag disappears. Then I package it up with Composer and deploy.
Keep in mind that you WILL be able to run Non-notarized apps* in Catalina by white-listing them in Jamf.
See here for more info on the changes coming for Mac Admins with Catalina.
*Now that I think about it, during the conference they said you would be able to white-list and run internal apps. I'm not sure if we can white-list applications from other vendors. Regardless of if we can pre-approve these apps from MDM, you will always be able to manually override the Gatekeeper setting to allow it to run on the local system.