I suspect that it won't work but wish you good luck. I included the batch to show how to manually create a BCD store as the instructions you had been provided would not have worked.
I will try your batch file, and report back with results regarding exFAT.
Microsoft deliberately did not include the WinPE-Wow64.cab package in the ADK, which is a required component for running 32bit apps on a 64bit OS.
This has been a problem in previous 64-bit versions of WinPE. If a 64-bit PE is required then the easiest solution would be to replace your 32-bit applications with 64-bit applications - e.g. use a 64-bit program launcher, file manager, etc.
Not the best solution, however if your goal is to create a minimal WinPE with a GUI replacing the command prompt shell then it's probably the easiest. It depends on how hard it will be to add 32-bit support and the increased size of boot.wim as a consequence.
My basic 32-bit WinPE contain only a shell (bblean - also available in a 64-bit version) and file manager (a43) within boot.wim - this keeps the size nice and small. A file manager can generally also be used as a program launcher.