If I have understood your question correctly, the Hi-Res certification is for the DAC (Snapdragon) in the phone itself. I think it will play up to 24/192. However, I wouldn't get too caught up in the Hi-Res certification marketing. I have the Oppo A5 2020 and think it is really good for music. So much so that I have sold my ZX2. There was no meaningful difference in sound quality and both have low powered headphone outputs. The Oppo has Dolby Atmos eq, which isn't actually too bad, not as good as Neutron, but still quite acceptable. With a good set of iems, I personally don't think you need anymore than this, unless you need to drive headphones or harder to drive iems.
I see. From this point of view , can we say all devices that have snapdragon 665 have same sound quality? Or does better snapdragon processor(for example 710) mean better sound quality?