That did it.
I removed the filter, ensured the DigiRBG.exe failed as expected.
Then ran the ..\Arduino 1.03 Digispark\Digispark - Example Programs\DigiUSB\windows driver\InstallDriver.exe, seeing it successfully installed the DigiUSB.inf
Then the DigiRBG.exe now works, along with monitor.exe. This makes sense as I see that libusb has a inf-wizard.exe, which is what you must have used to create DigiUSB.inf. I thought I read somewhere that no additional drivers are needed and noted that I saw the DigiSpark show up as a normal HID. Thinking it would work. I suspect this is the case for other applications that can access that HID directly. Whereas either the filter or DigiUSB.inf allows access to the LibUSB used by the python examples.
So I must have missed the instruction somewhere to install the DigiUSB driver (not to be confused with the boot loader driver).
Not being fluent in the supporting documents of this yet. I find the following, related to this subject:
..\Arduino 1.03 Digispark\Digispark - Example Programs\DigiUSB\readme.txt
..\Arduino 1.03 Digispark\Digispark - Example Programs\Digispark-Cheerlights\readme.txt
Both have the vague statement "Windows users should install the windows driver first."
and
..\Arduino 1.03 Digispark\Digispark - Example Programs\DigiBlink\DigiRGB Readme.txt
..\Arduino 1.03 Digispark\Digispark - Example Programs\DigiBlink\DigiRGBMail Readme.txt
do not reference it, at all.
I would recommend elaborating in each of the corresponding readme's and tutorials as to which driver is needed for windows. As it is easily miss interpreted as the Digispark_Bootloader.inf and not the needed DigiUSB.inf. Along with not being mentioned for those who start off with DigiRBG first and then work up to DigiUSB, as opposed to the reverse order.
Have Fun.