I assumed the reason it doesn't have one, and the reason VAC has it disabled by default, is so that people doing actual sound mixing won't have one more level control they forgot about that is effectively reducing bit depth. I find it weird though to say vb-cable isn't for audiophiles, yet it doesn't need a volume control. It doesn't help that these changes require reboots. I don't know if those are identical to the options in the vb control panel.

I used only the windows control panels, which do expose sampling rate options for the vb input and output devices. I did play around with matching up sample rates, but that was before I found the control panel.

No reason to give all the good stuff away. I suspect they aren't donationware, which is fine. I haven't checked out the other options but I will. But if you don't want to say you're providing a virtual sound device, just a cable, then we aren't talking about anything like a real cable, but just an application layer so-called 'cable' which has really no direct match in the physical world anyway, and so any analogy is whatever you want it to be. I still take issue with the 'real cable' analogy in the context of implying that it justifies some functionality or lack there of.

Best virtual audio cable control panel