We don't know, to be honest. (And if you want to demand more of us, you need to link your account!)
We have no access to Solidworks to test what it does. So few things use that kind of shell namespace extension these days that it's a virtually obsolete technology. A few things do still use the technology but not many and, even then, Opus can't add much value to them above what you get by using them in Explorer.
Even if it did work in Opus, most of Opus's functionality would not be available while viewing folders that Solidworks handled, since everything inside the file display would be drawn and handled by the Solidworks shell extension DLL, which has no knowledge of any of Opus's extra functionality. That kind of extension completely replaces the file display UI with one drawn by other software:
Opus would just be a frame around the Solidworks UI, and little else. You'd gain folder tabs and the ability to navigate to other folders using your Opus toolbars without having to switch back to Opus, but not much else.