Sorry, no suggestions for you, but just to note that within Tidal I only get one or the other option for my Pros.
Normally there is just a Connect option, but I have had a few occasions where one of the Pros only has a Chromecast option, and I don't know why.
A restart of Tidal and/or the Pro usually resolves this - i.e.back to just the Connect option.
As for 16 vs 24 bits, well, if it's the same stream then one surely can't have more than the other, right?!