wixsharp: Can't access CLSID registry in desired way

I’m trying to write some values in HKCR\CLSID, like so:

var project = new ManagedProject("Program",
    new RegValue(fullSetup, RegistryHive.ClassesRoot, @"CLSID\{6ED90329-F283-477A-83A3-97ADA22C02F9}\InprocServer32", "CodeBase", "file:///[INSTALLDIR]"),
    new Dir(@"%ProgramFiles%\Manufacturer\Program",
        new Files(@"..\Program\bin\Debug\*.*",
        file => !file.EndsWithAny(true, new string[] { ".pdb", ".obj" }))
        ));

however it always gets written to HKCR\WOW643Node\CLSID, even if I set project.Platform = Platform.x86;.

And looks like there is no method like ImportRegFile or ImportRegValue in project anymore, so I can’t set RegValue.Win64 to false.

What should I do?