I only skim read that I'm afraid (wide text format is awkward to read on a phone), but there are a couple of observations I'd make:
1) When you set default install location to sd (fat32 format) all it ever moves is the apk and some of the shared object files. That's how that is designed, the bulk of the installed app will indeed remain in internal, this is normal.
2) I've never used adopted storage (format sd card as internal), but certainly the higher-end Samsungs don't support it, and I wasn't aware that any did. If you use some trick to enable it then as that is unsupported there can be no guarantees of it working correctly.
3) The phone software is written to mount a single sd partition on boot. If you partition the card it won't look for a second partition. This is how all android phones have always been. Mods that use a second partition include extra software to mount the additional partition (originally init.d scripts, though I think that was deprecated years ago), so if all you've done is add a partition it's no surprise if the phone doesn't use it. Unfortunately it's 5 years since I last played with root so I'm not up to date with such things these days (the things extra partitions were used for generally required root).
