I have the same card. I used my computer to format as ExFAT. Then i put my movies, TV shows, photos, podcasts on the card from backups. I’ve already filled this card with the amount of content I’ve had. I also had to compress some files in order to fit it all on the card. In terms of google DRM. This content is stored in a hidden folder. The same with books. Google and other tech companies are trying to move to an all streaming future. They really don’t want people to have the content stored locally anymore. That’s why they moved google movies to YouTube a while ago. Google has a habit of closing apps that people use and its annoying. Anyway the benefits of having all your media on the phone is if anything happens you basically have everything stored on a device you take with you on a daily basis. I think that is the most useful thing about the 1.5tb SD card. I can’t wait for the 2tb. cards to be on the market. Then i wont have to have my content decompressed in order to enjoy it. I hope that this sorta clears things up in terms of DRM.
Location on SD card is Android/data/com.google.Android.apps.books is for DRM protected books (.apss.Movies for DRM movies) this is read only and gives this folder doesn’t exist error when opened on Android. A PC can read and back up this folder with a special program. Its just the way they try to hide this from a user.