LDAC automatically changing bitrate
LDAC changes bitrate compression automatically to prioritize stability. Even if you select best performance in Android developer settings, it will revert back to a lower setting.  Very annoying when using my ES100. 

Seeing the miracles you performed with the ES100 hardware, firmware and app, is there a way that you could lock the preferred LDAC compression on the  Qudelix side in the app so the user can control this?
Yes, Android OS resets the LDAC bitrate to the Adaptive(Best Effort) whenever the LDAC receiver reconnected.
It doesn't look pleasant, but unfortunately, there's no way to fix it at the receiver.

However, Adaptive(Best Effort) would be quite a reasonable choice, as long as you can take the initial startup low bitrate around 10 seconds.

At Adaptive(Best Effort) mode, LDAC starts with 330kbps and shortly goes up to 660kbps in most cases.
With some old version of LG smartphones and the devices with lower resolution display, LDAC quickly goes up to 990kbps eventually.

Galaxy S10 can't support LDAC 990kbps while the display is on. With Galaxy S10, LDAC 990kbps is available only with the screen off.
It seems that the high-resolution display system interferes with wireless communication.

Anyway, we'll provide a real-time LDAC bitrate monitoring feature.
5K reports the current bitrate to the mobile app, and the app displays and plots the bitrate graph.
We hope this feature would help you to use adaptive bitrate without a worry in most cases.

Thank You!
Qudelix, big thnx! It's very important information!!!
Fair solution. Great to see you active and doing your thing again!  Thanks!