Systemic overhead of shims - privileges

Question

I'm considering using shims to get around a game demanding Admin privileges (I tried editing the embedded "requestedExecutionLevel" tag with Resource Hacker and using .manifest files, but discovered the launcher software always downloads a new version of itself before running, thereby overwriting "asInvoker" with "requireAdministrator"). If I write protect the exe it exits with an error.
I understand that the shim required to spoof Admin privileges will probably add no appreciable overhead in itself; but MicroSoft's Application Compatibility Toolkit (ACT) that you need to install to enable shims uses a database to keep track of which application requires which shim. I'm sure this could be done with little overhead; but having seen MS' (and other corporates') past bloatware, I'm concerned my entire system will be slowed down if I install it.
Does anyone have DIRECT experience of installing ACT and KNOWS whether it slows the system down generally?

Answer 1

I've discovered you can add RUNASINVOKER as the value of a STRING key given the name of the application's full path here:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
and it will do the job without you having to install Microsoft's ACT package.
Example: if you had an application called Smeagol.exe in the directory c:\LordOfTheRings, then create a STRING key called:
c:\LordOfTheRings\Smeagol.exe
in
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
and give it the value of
^ RUNASINVOKER
and it will run without requesting Admin privileges.