Hi @Tommy74, welcome to our forum!
It is up to the developers of the application that you use to add an option where the recorded videos (I guess that is what takes up the most space) should be saved. In most of my applications where I can download offline movies, music and so on, there is a setting to either save the data to the internal storage or the SD card.
Have you had a look in the application settings and seen if such an option is available in the applications that you use? Most of the time you can access the settings by either tapping the three dots in the top right corner, or the three lines in the top left corner (if the developers follows the material design from Google).
You can also reach out to the developers as most of them have a contact Email address that is shown on their page in the Google Play store and see if they plan on adding such an option.
I hope that explains how it works at least!
