Default setting of "best effort" on my S10, mostly results in 660 kbs with Q5K. From experince with S10, 990 kbs usually stutters, so anyway I have to reduce it to 660.
I did try PEQ settings for several headphones (SE846, FiiO FH7, Beyerdynamic T5p). Eventually I prefer to leave EQ off. I listen to Tidal HiFi via UAPP, set to Bit Perfect.
I had that issue on my S9 with the ES100 where 990 just stuttered constantly so I left it on the default setting. With my V60, I still leave it on Best Effort (Adaptive Bit Rate) and the Qudelix app will show 990 moat of the time (sometimes 660 but then go back up to 990). At least with the V60, you dont need to force 990 in Developer Options to get 990. Works and sounds great. I found the BT connection/LDAC to work much better on the 5K vs. ES100 as well (even on my S9).