Complete Install R2R Steinberg Activator-NoOne

Yes, by using Inno Setup and the official microsoft certmgr.
I already did that for myself but I didn't share it on AZ as I thought sharing repacked stuff from R2R isn't allowed.

You have to install the Windows SDK and after that you can create a batch script to install R2R's cert which looks like that:

@echo off
certmgr.exe /add R2RCA.cer /s /r localMachine root
exit

After installing the SDK, certmgr.exe is located in:
C:\Program Files (x86)\Windows Kits\10\bin\10.0.22000.0\x64
Just copy it to the folder where your batch script is.

You could also create an inno setup script to install the cert by adding the code:

function InitializeSetup(): Boolean;
var
  ResultCode: Integer;
  
begin    
    Exec(ExpandConstant('{src}\Setup\certmgr.exe'), '/add R2RCA.cer /s /r localMachine root', '', SW_HIDE, ewWaitUntilTerminated, ResultCode);
end;

the folder structure in my example looks like this:
SourcePath\install.exe
SourcePath\Setup\certmgr.exe
SourcePath\Setup\R2RCA.cer

'install.exe' is the compiled Inno Setup script.

By adding other lines to the script, you could create an installer that not only installs the certificate but also vcredist, the silk emu, cubase12 itself and its required components. That's what I did for myself.

Maybe it's just to verify the validity of the certificate, true!