EDIT: Agh, what a waste of time. It seems that when you write a game using diskwriter, it somehow manages to eat the secondary partition to give itself more space =/ (Read Post #4)
I know this is a really tacky and unorganized thread, but it still gets the point across. You can click the pictures to view a much bigger version.
Ordered two 16GB MicroSD cards alongside my Sky3DS which won't arrive until Thursday, but the SD cards came in today and I can't find the 4GB card I planned on using for my R4i 3DS. So I had the bright idea of: What if I could just create multiple partitions?
As anyone with a Sky3DS knows, once you use Diskwriter with that SD card:

As indicated by Disk 7, the entire SD card's space is reserved for Sky3DS.
So I used EaseUS Partition Master to take some of the unallocated space(must be some weird partition that only Sky3DS can read?) in reserve for my R4 and made it a FAT32 format and marked it as a Primary Partition.

Now for some reason, Windows 7/8/8.1 doesn't read multiple partitions on removable disks

But from this EaseUS screenshot, you can clearly see that the partitions are still there:

Using a program I found called SDMinste(Only 268KB, you can download it here), it can detect multiple partitions on an SD card.

Click Swap Partitions, it does just that, you take the SD card out and then put it back in, and the second partition loads so you can edit that as well

Switching back to Sky3DS's Diskwriter, it still for some reason shows the SD card as having 15GB of available space(and after writing a 1GB rom, it says 14GB space), but it's still able to write the game, so clearly that partition despite being smaller, it can still be read at least somewhat correctly by the diskwriter, so I assume it could read correctly in the Sky3DS too.

So can anyone test this? Leaving the Sky3DS partition as partition #1 and seeing if it still works fine in the Sky3DS and seeing if the R4 looks past the "unallocated space" part and sees the FAT32 partition(that's the main reason I wrote it as primary.
My best guess about how this will work is that, every time you want to change between R4 and Sky3DS, you need to have a computer next to you to switch between the Sky3DS and R4 partitions. While it's still better than nothing, I wouldn't deem a desirable result.
I know this is a really tacky and unorganized thread, but it still gets the point across. You can click the pictures to view a much bigger version.
Ordered two 16GB MicroSD cards alongside my Sky3DS which won't arrive until Thursday, but the SD cards came in today and I can't find the 4GB card I planned on using for my R4i 3DS. So I had the bright idea of: What if I could just create multiple partitions?
As anyone with a Sky3DS knows, once you use Diskwriter with that SD card:

As indicated by Disk 7, the entire SD card's space is reserved for Sky3DS.
So I used EaseUS Partition Master to take some of the unallocated space(must be some weird partition that only Sky3DS can read?) in reserve for my R4 and made it a FAT32 format and marked it as a Primary Partition.

Now for some reason, Windows 7/8/8.1 doesn't read multiple partitions on removable disks

But from this EaseUS screenshot, you can clearly see that the partitions are still there:

Using a program I found called SDMinste(Only 268KB, you can download it here), it can detect multiple partitions on an SD card.

Click Swap Partitions, it does just that, you take the SD card out and then put it back in, and the second partition loads so you can edit that as well

Switching back to Sky3DS's Diskwriter, it still for some reason shows the SD card as having 15GB of available space(and after writing a 1GB rom, it says 14GB space), but it's still able to write the game, so clearly that partition despite being smaller, it can still be read at least somewhat correctly by the diskwriter, so I assume it could read correctly in the Sky3DS too.

So can anyone test this? Leaving the Sky3DS partition as partition #1 and seeing if it still works fine in the Sky3DS and seeing if the R4 looks past the "unallocated space" part and sees the FAT32 partition(that's the main reason I wrote it as primary.
My best guess about how this will work is that, every time you want to change between R4 and Sky3DS, you need to have a computer next to you to switch between the Sky3DS and R4 partitions. While it's still better than nothing, I wouldn't deem a desirable result.