How to expands sd-card formatted as internal storage? In Android 6 I formatted my 32GB sd card as internal storage.
What I now see with GParted on my desktop is this:


As you see there is still an unencrypted, readable FAT32 partition.
I assume it was created when formatting this sd card, because there I still had some large ZIPs (previously used for flashing) on my sd card.
I am a bit surprised to see that the data is still there - especially as the guide when formatting the sd card clearly states all data will be removed.
Possibly the files are also added afterwards as I used TWRP to copy some files to /external_sd even after I did this.

So I deleted the unnecessary ZIPs on my PC and now I obviously have unused space on my sd card. So: How can I expand my sd card?

It is also interesting what Nemo shows me:


The yellow parts are the used space (98,3 kB) and the blue on is empty (31,4 GB). It also claims the file system would be msdos...

Just FYI: Besides my ZIPs there are also empty folders called "Android" and "LOST.DIR".
Not knowing exactly I believe that Android 5.0 and newer has gone and caused protection on orphaned memory space.  I would like to know more about situations like this.