And what do you get in admin command window with
fsutil wim enumwims J:
Then I got: I:\Wimboot\10-WB.wim:2 the full path and the image index, 2 in this case, attached images of Power Shell and Command prompt.
EDIT: The following command is valid for both VHDs 10x86 and 10x64, created respectively from 10-WB.wim image 1 and image 2, if I want to relocate the coupled Wim-VHDs on primary partition of external device:
Run as admin directly on each attached VHD drive:
DISM.exe /Update-WIMBootEntry /Path:J:\ /DataSourceID:0 /ImageFile:K:\Wimboot\10-WB.wim
J:\ Is the attached VHD located on internal HD, before copy it to USB, latter if you want it can be copied to K:\ root,
I made this before copy the VHD because if I want to only Ramboot and then make a LZ4 compressed VHD (only can be loaded in Ram, and only work if made from a fixed size VHD) it is faster to do it on the HD, and latter copy to USB only the 10x64-WB.vhd.lz4 (130 MB) and 10x86-WB.vhd.lz4 (99.2 MB) as required (and not the full 1.5 GB for each fixed size VHD).
Or if for any reason I want to be able to also boot from bootmanager and not only Ramboot the OSs (very improbable for me since Ramboot is IMHO the best and fastest option) then I need to make and/or copy 480 MB for the expandable 10x64.vhd and 360 MB for the expandable 10x86.vhd.
K:\Wimboot\10-WB.wim is the wim file already copied to single primary (NTFS) partition of my external USB device.
All BCDs and grub4dos menus were made manually.
So just applied this command to 10x86.vhd and also the same to 10x64.vhd to relocate the files.
By the way I have a new addition to moded WimBootCompress-2019-03-31.ini (attached).
\MSOCache\* >>> This is the hidden cache folder after installing Office (saving to compress in your wim file from about 300 MB to almost 1 GB, depending on version), sometimes it may be created on other partition if available.