Even with “show hidden devices” enabled and checking all the categories in the device manager there are no entries for these two DACs. I found a third one, though, which is interestingly not shown in Roon.
Checking regedit, this seems to be the place where the entries are located:
Does this help? I’m not familiar with how drivers are installed on a PC, but the bit about ‘USB Composite Devices’ looked like it might be relevant.
No, thats because ASIO drivers work in a different manner. But basically you have installed crappy drivers which doesn’t uninstall properly.
So, your options are to either accept the inactive sound devices in Roon (not a Roon issue per se) or “hack away” in the registry.
Or consider a reinstallation of your OS which will of course remedy this also! 
Similar situation to original post, but not exactly the same. I recently tried to make a grouped, stereo pair thru the Denon head app (home 150 speakers). The devices all have the latest software and the instructions are very simple, however it never worked (will call their tech support). Ha I said all that, in the testi created a bunch of new speakers in the heos app (“test”, “test2”, “right”, “left”, etc). None of those devices remain actual devices in the heos app, yet remain in roon. Most of it is garbage, so just from a cleanliness and management standpoint, would love to remove all the fake devices that no longer exist.
Theres a shortcut also, but i take no responsibility for it:
Look in your Roon Server folder(or maybe its the RAAT folder), there’s a Devices-folder in it. Withing that one there are multiple items named like GUIDs, 3EF12635AD37123
Each of these represent an audio device on that machine, and they can of course be removed.
