I’m not really big on the upsampling thought process as I believe that if the gear can’t reproduce 16/24/32 bit audio in the first place there’s no point in worrying higher sampling rates.
So much of this depends upon the design and build quality of each component as well. From what I’ve read in your first post I would start with comparisons between your SACD players output and how that compares to streaming content. If you’re playing CD’s this will be more of an apple to apples comparison. Note the differences of what you like or not and start your focus there.
I use a Naim Uniti Core to store/playback my CD’s. I have a lower model Lumin U2 Mini transport for streaming. Although I listen to the music through the Lumin almost everyday I still prefer the sound of the ripped CD from the Naim- regardless of what format or sample rate the Lumin is streaming the music in. I run the Lumin native- even though it will upsample to 512 or something crazy it’s always playing the file in its native format.
My point with this to start simple and work with what you have from a basic level rather than being lured into what seems to be greater features. You may find in the end that they really don’t perform with that great of a difference or that the gear you’re using isn’t really that good at performing them anyway. If you start with a basic comparison- CD player 16/44 Redbook through your chain vs streaming 16/44 through your chain you’re able to analyze the difference. Use that a while and get comfortable before moving up to comparing CD against upsampled streaming content. You may find that those features aren’t really that important to you and if they do turn out to be at least you’ll have invested the time into discovering the nuances between both. Have fun and enjoy!