Is that specific phone using a special unknown partition system for the card? I don't think so. The phones are this days build with market standards including SDHC and SDXC compatibility. SDHC natively use FAT32, SDXC natively use exFAT. Not all phones support SDXC so the card have to be formatted in FAT32 to make it functional and the only way is to use specific application on PC. Formatting the SD on PC also is more efficient than OS of the phones and the main reason is that OS of any phone can't verified a faulty or fake SD card so you can losing data without even know why.
I have never seen or heard of an Android phone which didn't use FAT32 or exFAT, nor one that made arbitrary partions. Further, if the phone doesn't support exFAT, obviously it won't format the card to use the exFAT file system. The bit about a PC being more efficient is just total nonsense. I have formatted several different size/brand SD cards on this phone and others without having issues using them in the phone or a PC or other Android device, even. If you can satisfactorily back up anything you've said, I'll change my mind.