reversing "Windows To Go" -what am i doing wrong?

Hi all. Hope this is in the right sub-forum but please advise if it is not.

OK - so batting my head against the wall here...

Have windows on external drive (was converted to windows to go from internal hdd using wintousb) - this works fine with steamdeck.

Upgraded internal ssd, cloned steamos from old ssd to new one and installed a fresh windows installation. After a bit of tweaking both OSs boot and work fine.

Now, my goal is to replace the fresh install of windows with the one from the external SSD (TDLR my kid's machine and he installed ton of bits of software from all over the place which he doesnt want to lose)

SO, I have tried to clone the partitions from the external drive into the space occupied by the fresh windows install using Macrium Reflect. I have first used wintousb to convert the windowsToGo to local windows on the HD.

Steamos boot manager gives me the option to boot from windows boot manager but all results in BSOD.

One curiosity. I have tried it few times, each time converting the external HD from WIndowsToGo to Local Windows and back again after the installation failed and my son wanted to use windows in the meantime. My last attempt I didnt convert back yet the external drive boots and work just as before so I am wondering if wintousb actually convert back like it suppose to do... is there a way to check this as i google everywhere and cant find any information on what is actually changed by Wintousb