Windows installer won't allow me to install on an external SSD

[niekvlessert]

I can use Wintousb to create a installed Windows 10 running from an external SSD on a Mac, however getting that to Windows 11 is not doable afaik. With Windiskwriter I can create a USB disk to start the Windows installer, but that won't allow me to install ot external SSD afaik. How to get to my goal of running Windows 11 from an external SSD?

I think it might work if your software allows me to create an ISO file instead of writing to a disk/pendrive. So I can then install that ISO using Wintousb?

Or do you maybe see other tricks? Maybe fixing the Windows installer to allow me to install on an external drive? Or...?

[niekvlessert]

I just found out about the 'Install Windows 10 and setupprep.exe /product server to upgrade to 11 thing', haven't tried it.