Steam Quality Swisscom Box vs Blu App

Hello

You can now get Swisscom Blu TV via the box itself as well as via the app. (E.g. LG Smart TV app)

How does the quality of the stream differ? Is it better via box than via app? Using the app I would have the advantage of being able to have the HD signals from the TV upscaled to 4k. However, you pay 5 francs if you need the app on the TV if you already have a box. I’m not interested in the delay, but in the pure image quality in HD. 4k is not yet possible via the app.