Not much to say yet except it works.
Start Rufus as Admin. There were a couple files it couldn't access during my process. I still worked but best practice I didn't think about.
The two I've done with Rufus I chose GPT so it only boots with UEFI. (see below)
I saw I video where selecting MBR will allow booting both ways. Need to try.
I stuck one on SATA in a Linux machine and dual boot with the F key. I do get an odd warning to "keep the USB device attached" that I don't get when actually booting from USB.
All the drives in the PC are accessible.
This may be a good way to run/install Win11 from an incompatible PC that refuses the standard bypass of TPM. Not sure that ever happens.
I think this is the way to make it bootable in both UEFI and Legacy but I neglected to do it.
AOMEI Partition Assistant claims ability to create WinToGo from a current system.
EaseUS also has a solution I guess.
WinToUSB may also be a good option.
When you first boot WinToGo it goes through setup which went fine over ethernet.
On wifi it no driver. Even when I installed the driver it didn't work.
Maybe when I get to an ethernet connection that will all clear up.