Can I put one user in Standard mode, and another SUA user in lockdown mode?
I tried enabling lockdown without GUI, and not enabling GUI for the other SUA user, but after a Windows update, the other user could not get to desktop.
There are 2 types of Settings: global system-wide and local user-wide.
Interface tab of Settings and lower part of Log tab are local user-wide settings. It means different real users can set different settings for them, for example use different GUI languages.
All other settings are global system-wide. It means they are set globally for all users.
ReHIPS Working Mode being one of "all other settings" is a global setting. So nope, it's not possible to set it into different positions for different users.
P.S. Lock-Down Mode, especially combined with Expert Mode is a tricky thing. If your environment is stable like the one on payment terminals, it's a perfect choice to automatically block any unwanted programs. But in a volatile environment like desktop which is updated, new programs are installed and deleted, it may be too restrictive.