The generic import files in the VCL, RTL and Extra folders do not have includes for the XE8 import files. The highest version referenced is XE7. For example:
You stated in another thread that the import files have not changed since several versions prior to XE8. I see how this could work if I have one of those previous versions of Delphi installed, but if I only have XE8 installed the import files for those prior versions (such as XE7) do not get installed. I have had to add the include ($I) statement for XE8 to many of the import files to get it to work.
Did you installed TMS Scripter using the installer, or did you manually tweak your Delphi IDE to use scripter files?
The files used by XE8 are the same as for XE7. There are no specific XE8 files.
The source code folders with import files are always present no matter what Delphi version you install scripter to. I don't know why you came to a different conclusion. Even if you install only in XE8, all import files for previous versions are there.
Finally, I don't see why you would need to change the include directive if it states that {$IF CompilerVersion >= 27} which means that any version above or equal XE7 will use those same files, be it XE8, XE9, XE10, etc.