Wow that's a nice setup you have there!
I was nearly buying a pair of focal electra (monitor size) 4 years ago to m8 with a push pull tube amp, and was hesitating between those and Cabasse Artis but I went with active crossover and multi amplification instead and also because I'm a long time meridian fanboy. Love the french touch but love the english sound better!
I "only" have Meridian DS3100 speakers, they are rather "monitor" like sounding but the three speakers configuration help the bottom end a lot and I always disliked sub.
Your system seems way more expensive than mine. While my common drivers are optimized through dsp and tuning, yours are top end and futuristic by the reputation of focal. Why using the little SBT with those glorious loudspeaker and amp? You got to feed it with a higher end source, it would mate better I guess. I never heard a Yulong, is it really that good for you to have chosen it? I would have chosen a more reputable DAC manufacturer IMHO.
You might have noticed that headphone listenning is pretty sensitive to tonal change and micro information retrieval, that is why I judge TT 3.0 through the HD650 and LF339, but the quality jump in my digital speakers is pretty spectacular as welll!
I would dream to have a Meridian Sooloos streamer but it's out of my budget right now and seeing how good the SBT now sound I won't climb that train. But for you I bet you'd appreciate the upgrade. I suggest those because I trust this brand, but I'm sure there are better streamers than SBT out there too!