What you may not have realised is that you need to dotsource exes as well as .ps1 script files.
In the same way that you must prepend a powershell script with .\ in order to execute it e.g. .\ripper.ps1, you must also prepend exes with .\ if the directory containing the exe is not in your PATH statement.
I was trying to run Microsoft’s devcon utility (devcon.exe) within Powershell from a backwater directory not in my PATH like so:
PS c:\backwater> devcon
Nope. It has to be dotsourced.
PS c:\backwater> .\devcon
Dotsource your exes or stick the directory in your PATH.