A question regarding upsampling, dither and s/pdif

[Heavy Jerk]

So earlier this day my Profire had finally took a ****ter, and after that I sent it off to be serviced. There's one problem bigger than that though - I have a project to finish. So, I am stuck.
As I use my i7 laptop for audio production (has far better specs than my old desktop), I am pretty limited in options. It has an s/pdif out, so I figured that I could connect it with my desktop, which has a decent sound card in it, which also has an s/pdif input.
So I want to use it to monitor mixing. I can't hook my monitors up some other way.

My laptop sound card defaults its s/pdif output at 48kHz 16bit. As I mix 44kHz 24bit, I would use Asio4All driver for upsampling (44.1->48).
But, since I am changing bit depth too, my question is - should I put a vst dither plugin (24->16) to run in real time on my master buss?

Cheers