I've tested resizing a few months ago:
PQMagic doesn't recognize a valid partition -> resizing is not possible
Acronis Disk Director Suite:
knows the partition (not as WBFS, but as one with data).
Tested first with a small partition with data on it and a 100GB HDD. My intend was to create a FAT32 in front of the WBFS partition.
My starting position was:
[--------------WBFS---------------]
1. Shrinked the WBFS
[------------WBFS---------][FREE]
2. Moved WBFS to the end of the HDD
[FREE][------------WBFS---------]
3. Created FAT32 in front of the WBFS
[-FAT32-][---------WBFS---------]
After this i tried to start every game on the wbfs partition with gx and it finally worked.
Now I tried this procedure with my 1TB HDD (with over 200 ISOs)
The procedure finally ended with no errors, but not one of the ISOs would start in GX nor the partition is recognized as WBFS with any WBFS Manager (or within GX).
So the final output is: you can try it, but be sure to have a backup of your data, because it can be destroyed during the process.
GOOD LUCK !