I can confirm that indeed, it is very unstable. trex dev himself recognize it:
A few tips if you experience frequent LHR locks:
Make sure you don't have monitors connected to your LHR cards, or at least turn them off during miner start up to let it calibrate correctly. Avoid using RDP if it puts load on your LHR cards.
Do not delay applying overclock - this will mess up calibration results and the miner will display unrealistically high LHR tune values.
Try reducing memory overclock of the GPU that frequently trips LHR.
So what do you do when it have "frequent locks" ? You lower your mem clock, again & again until this release become unsuable and you're better to go back to 0.25.8
nice try tho