Reviewing things today it seems the rule is:
Higher Resolution wins with the following caveat, at equal resolution MQA is treated as the better resolution.
So, if there is a 24/44.1 Qobuz file and a 24/44/1 MQA Tidal file then the Tidal file will be chosen. Same goes for 16/44.1 resolutions.
This flips though at 24/96 and 24/192 Qobuz are chosen in preference of the 24/48 96 MQA / 24/48 192 MQA. So, it is comparing the base file resolutions and ignoring the ORFS in the comparison.
This is all further complicated by it seems to be only comparing like versions of the album. See below for a better example of this. I got a Daily Mix today where the chose was a track from ELP Trilogy see:
As you can see the 44.1/16 MQA was chosen. But, if you look in Versions you see this:
And, this next part is why I think it is confusing for us (I might be completely wrong but every instance I looked at bore it out) I left it big so you can see. From the above ELP example, there are 3 Trilogy verions available in Roon for each service AND Roon nicely groups them all together as “versions”. However, they are not all compared against each other.
When Roon randomly selected the Album/Track it seems to only compare the options between the exact equivalents between the two services. So, in my case it chose the second version and compared it to the second version in Qobuz, and using the above rules the Tidal 44.1/16 MQA wins out (As shown with the Currently Viewing text and track circled in red). What it does not seem to do is compare across the different versions. If it did, then the 24/96 Qobuz of 2015 Remaster is the one which should have been chosen.
This pattern was replicated in each instance where a 16/44.1 MQA track was chosen, yet, a 24/96 Qobuz track existed. For example, here is Jethro Tull’s Stand UP, the Tidal 44.1/16 MQA was chosen (circled red in pic below), but, as you can see, there clearly was a 24/96 Qobuz option with a different version pair.