Upsampling is almost always done better on the server side, but...
There are a lot of caveats.
It is very difficult to get a good signal from a PC's USB port, especially if it is not a dedicated server that is optimized for audio. I have never been able to get good results from any of the PC's I have built for general use over USB. In my experience, ethernet better.
Adding the CPU burden of upsampling will not make things better if the PC has trouble making a good output at idle even though 192/24 is pretty easy to get.
JCAT and some others make fancy USB boards, but you still need a fancy power supply. It will cost less and be less hassle, and probably sound better to just get a dedicated server.
I suggest making a test. Use Fidelizer Free and see if it improves your playback - if it does, consider rethinking your approach to digital playback. This can get really complicated really fast, but you can load Daphile onto an old PC and get very impressive results for free. Plus you get to control things from your mobile device. I did this for a long time and did the upsampling on an RPi based USB bridge. It was worlds better than using my PC. I expect your BUC would be even better.
Currently I run HQPlayer Embedded and Roon on a dedicated Linux server. I had to dust off the old system recently when the internet was out for a week and I was impressed with how good it was for a very modest price.