R2R relay volume vs. digital volume

[Jazigo]

Sure, there are two obvious options: Wiim and Bluesound.
Wiim has no 'loudness', so I would have to choose manually EQ preset. This is not as convenient as Audyssey Dynamic EQ in my current entry-level Denon S650H in living room.
Bluesound entirely screwed basic tones control per user's feedback.

So I have to do proceed with research and look for something less obvious.
For this, I would like to have some check list and volume control that do not harm too much is among them.

What should I check for? I plan to use Spotify lossless and some flacs. Should it be something like 64bit internal processing or some dB range in specification or DAC ship?

Given the best possible scenario, which is digital volume control in the dac with power amplifier where you can adjust the gain (the actual gain and not signal [preamp]):

Look for a really good DAC chip which have high SINAD and SNR. SINAD > 120db and SNR > 125db. Make sure that the volume control on the streamer is actually is done by the DAC. The DAC chip should be from ESS or AKM, since they are the safest bet. Other can be good, but I would definitely research those chips hard before trusting them.

Word of caution: Going outside of what have been tested here on this forum can be a rough ride. Their will be wild claims or none at all (they keep back vital information), so navigating it would be difficult. I usually assume most is garbage until proven otherwise.