Sourcemaps, Ionic3/Angular4, release builds and phone apps

I’m curious if anyone has been able to get sourcemaps working with Ionic 3/Cordova release builds deployed to phone apps. It appears as though the sourcemap files are being included in the apps, and the proper referneces are at the bottom of each .js file in those packages. However the source maps do not seem to be getting picked up by Sentry.io.

Short of moving to releases, something we will likely do in the future but cannot at the moment, is there something extra that must be done to get source maps working with release mode Ionic/Cordova apps released to iOS and GPlay app stores?