Tested: Portable
The "Portable Version" is a little misleading, it's a .ZIP file which contains the Setup file. Therefore you have to UniExtract this file and Launch ERUNTgui.exe that is stored in "setup\{app}\files\"
I don't think it should be added to TPFC, because as you pointed out
ERUNT is in the database and it seems pointless for something like
ERUNT which isn't even convoluted! It's like creating a PortableApps wrapper for CCleaner!