[Xiaomi Mi Pad ROMs, Kernels, Recoveries, & Other D] Cezar`:
Posting here for posterity.

If you used the Mi3 resize script, that resized the wrong partitions.

Mi3 has

/system on /dev/block/mmcblk0p25
/system1 on /dev/block/mmcblk0p26

MiPad has

/system on /dev/block/mmcblk0p26
/system1 on /dev/block/mmcblk0p27

On MiPad /dev/block/mmcblk0p25 (the one wrongly resized) is known as BKE

[partition]
name=BKE
id=30
type=data
allocation_policy=sequential
filesystem_type=basic
size=4194304
file_system_attribute=0
partition_attribute=0
allocation_attribute=8
percent_reserved=0

I am unsure what the purpose of this partition is. I was unable to mount it to see it's contents.

Also, simply trying the Mi3 restore script might not work because of the subsequent changes to the NAND that happened by flashing the fastboot ROM package. I also assume you attempted to use the MiPad resize script as well. The problematic variable is the size and the span over which BKE extends. Because the size of BKE was modified to be 1.2GB in size (originally 4MB), you can imagine that every other partition was affected in one way or another, Including WB0 (which you're having problems flashing). Not sure how it happened exactly, as WB0 is way before the position where BKE is, so I leave that to an experienced dev to answer.

The fastboot ROM package, also, does not repartition the NAND as I can see from the script, so maybe the people that created that package can help you with some solution, maybe a package that also repartitions the NAND. I know on Galaxy S there would be the option to "re-partition" the phone which would be very dangerous but in your case, it may be one of the few options to recover the tablet.

Nonetheless, I looked at the layout of the NAND to see where precisely on the NAND is BKE. At the same time, we can also see exactly where all partitions are located.

~ # fdisk -l /dev/block/mmcblk0
Found valid GPT with protective MBR; using GPT

Disk /dev/block/mmcblk0: 30777344 sectors, 2740M
Logical sector size: 512
Disk identifier (GUID): 27c2d087-d865-8963-7669-ad89940602bf
Partition table holds up to 29 entries
First usable sector is 4096, last usable sector is 30773247

Number Start (sector) End (sector) Size Code Name
1 4096 8191 2048K 0700 NVC
2 8192 12287 2048K 0700 RMB
3 12288 28671 8192K 0700 EBT
4 28672 45055 8192K 0700 RBL
5 45056 53247 4096K 0700 DFI
6 53248 61439 4096K 0700 TOS
7 61440 63487 1024K 0700 EKS
8 63488 67583 2048K 0700 FB
9 67584 69631 1024K 0700 WB0
10 69632 77823 4096K 0700 MSC
11 77824 131071 26.0M 0700 USP
12 131072 139263 4096K 0700 MDM
13 139264 147455 4096K 0700 MLO
14 147456 155647 4096K 0700 MRO
15 155648 196607 20.0M 0700 BKB
16 196608 229375 16.0M 0700 PST
17 229376 245759 8192K 0700 MDA
18 245760 262143 8192K 0700 LOG
19 262144 270335 4096K 0700 MRW
20 270336 327679 28.0M 0700 BKC
21 327680 393215 32.0M 0700 BKD
22 393216 434175 20.0M 0700 LNX
23 434176 475135 20.0M 0700 LN1
24 475136 516095 20.0M 0700 SOS
25 516096 524287 4096K 0700 BKE
26 524288 3136718 1275M 0700 APP
27 3136719 3145727 4504K 0700 AP1
28 3145728 3932159 384M 0700 CAC
29 3932160 30773247 12.7G 0700 UDA

What you need to do is run the same command on your tablet and see what is the output.

fdisk -l /dev/block/mmcblk0

Run the command while in recovery and while connected to the PC via adb shell.

Post the result here and then we'll know where we stand.