No one else has reported a prob, but ...
Using Windows 10 LTSC 2019 64-bit & LTSC 2021 64-bit, both have been lited using MSMG Toolkit.
When I run imdiskinst 2.1.1.exe I get a error popup - see attached pics.
If I extract the exe using 7-zip and run install.cmd, it installs OK.
imdiskinst 2.0.10.exe installs OK either way on both OSs.
Installs OK from install.cmd: