Last I checked, the kernel maintainers haven’t accepted the RST source code provided by Intel to officially support it under Linux.
Your best bet is to disable it in the BIOS, and use the two “separate” drives, as they will be displayed by the installer. However, this will effectively wipe your current Windows 11 installation.
With the recent changes done to the Manjaro installer (Calamares), the above linked thread suggestions have been implemented, and so it should successfully install and boot, without needing to make any additional manual changes. (However, there are two additional distinct changes that you can do yourself, if the defaults still don’t suffice.) I listed all three in the linked thread.
Keep in mind, this will not work if you have RST enabled in the BIOS.
Also keep in mind, disabling RST is a one-way process if Windows 10/11 was already installed on the system.