Wow, yes that would be really irritating.
I had a KT4004 for some time. I used it with iPad, iPhone, a DeLock USB 3.0 hub, a 3.0 Western Digital bus-powered drive, and two 3.0 Western Digital AC-powered drives. All worked fine, but admittedly I never used the KT4004 with Yosemite.
I was forced to upgrade to Yosemite recently, and everything still works fine. I have a different card than you do, but it does have the same chipset and uses the same drivers.
I'm curious what kind of devices you are having issues with. I recall some people having problems with specific-chipset drive enclosures, certain hubs, one specific memory card reader, and the Nikon D800 camera.
I frequently use a Sandisk Extreme USB 3.0 thumb drive and have problems with that, but it's not just that...it's other devices, but it's random and infrequent. When it happens, I usually wind up plugging into one of the front USB 2.0 ports!