Your thinking seems about right, though I'm no expert at what a BV such as a Harmony sends down its Powerlink to the 50s
I'd also not worry much about 24/192 vs 24/96 etc - the amount of 24/192 music on Qobuz is very small (I use Qobuz myself).
I did get a separate streamer / DAC unit for direct connection to my 50s. In part that was because I wanted a Roon capable device into my 50s, in part I wanted some access to content above 16/44 (not that I'm obsessed by that), and in part because the analogue out from the DAC into the 50s (i.e not USB) sounds better than routing the Digital out from the streamer / DAC through my BV to the 50s.
So it was driven by 3 aspects.
If you find casting Q from your phone to the Harmony a fiddle, then sure - I;d just get a streamer with native support and connect direct to the 50s.
To me though, the biggest improvement in quality in my setup comes from feeding the 50s from an external DAC via analogue. The same streamer / DAC has a digital out - i.e not using the DAC part, and that digital out (through my BV) to the 50s sounds fine but appreciably worse using the DAC part.
But even when listening via this preferred method (analogue out from the DAC to 50s) - the difference between 24/96 and 24/192 content isn't appreciable.
So I would not sweat it, in my humble.
ok, so could you confirm that my thought process is correct? here is my goal: get the best sound out of the 50s for listening in stereo...
First: Source: so far the only source i plan to use is streaming audio. So far, for my purposes, it seems Qobuz is the best option for loseless HIRES (24/192) streaming. Obviously this is accounting for the original source recording quality and im not talking about upconverting or anything. Qobuz seems to be the only loseless 24/192 out there, MQA is not loseless and has its own issues with the folding unfolding process, both with loss of data and added data.
Second: Connection from "source" to the 50s: the best option with as little back and forth from D-A A-D would be have a streaming unit such as a core or another manufacturer that is hardwired to the ethernet and has Qobuz or another HIRES app that it natively runs and therefore my phone is just "controlling" the functions of said app. Therefore i am not throttled by the limitations of googlecast which is 24/96. THEN, if i have a high quality streamer, connect that directly to the 50s via USB, which would support 24/192. (optical/TOSLINK is limited to 24/96 no? you mentioned 192 earlier but is that correct?)
Third: If i choose to just stick with casting my qobuz phone app to the harmony then i should be able to retain 24/96 to the harmony and then from there it converts to A via its own DAC and outputs that to the 50s over PL at 24/96. Then that signal reaches the 50s which converts it back to D via the DAC in the 50, does some fancy processing, and then outputs the sound. Am i following correct? And am i correct in my understanding that the Cat 7 cables that are connected from the PL out on the harmony to the PL in on the primary 50 carries that 24/96 signal in analog form? I just want to make sure i understand that the Cat 7 cable is carrying an analog signal of the original digital 24/96 source from Qobuz.
If this is all true then i may just save the money in my quest to achieve 24/192 given my current setup as it sounds like there is no way to output 192 to the 50s via the Harmony. I would have to have a digital streamer that can support that output and then directly wire it via USB or S/P DIF to the 50s to get that quality.
Sorry if this seems scatterbrained, its a torrid landscape up there. lol thanks for any and ALL input on this. im really trying to make sure i have a good handle on this topic as it seems to answer a lot of later questions when troubleshooting connections and trying to get the most out of these awesome speakers.