Understood, thanks.
I suspected as much, but there's a short history here. I've been using the Inateck card for a while now, but I wanted simultaneous data & charging for the iPad like I can do with the iPhone. I've tried two different USB 3.0 hubs, both with more than large enough power adapters. I could sync, but could not get the iPad to charge.
Trying two different hubs seemed to me to rule out the hub as being the problem, so it seemed logical to ensure the other part of the USB chain, the card, was also powerful enough to charge the iPad. So I upgraded from the Inateck to the Sonnet.
But it's still not charging. So I'm starting to think that simultaneous iPad charging and data are not possible, in part because I see lots of USB 3.0 hubs with dedicated charge ports that do not connect to power. But that doesn't really make any sense because the USB 3.0 specification allows for enough power to charge an iPad in the first place.
So I don't really know what's going on. But I've spent too much time and money on this already so unless the KEXT magically fixes the problem, I'll just have to charge separately or run some kind of extension cord directly from the card--something that I was trying to avoid because hub charging+data seems like it should be possible.