Sorry for a long silence, I've been “enjoying” myself with testing. Instead comes a long text with how I came to what seems to be a perfectly stable environment. Googling my errors I’ve found out that I’m definitely not alone with these BSODs connected to “Driver_power_state_failure”, especially connected to the Adobe Photoshop family of products. Obviously Windows requires a lot more of your PC and so does the latest updates of the Photoshop products. There are numerous more or less odd and homemade “solutions” that work for some, and not for others. I tend not to go for them since they often create even more problems and are difficult to [remember an] revert. Instead, I stick to standard solutions. This worked this time as well. None of these settings were necessary with Windows 10 and/or the earlier versions of the Adobe products. It can also be noted that before I started with HWMonitor I couldn't let the laptop go into sleep mode. That resulted in a rebooted PC when I woke it up again. That behaviour seems also to have disappeared.  So, in short, make sure you have all the latest drivers, increase memory, give the GPU full power and make sure to cool the computer. New Windows and Adobe products seem to need it. Hopefully this will be a stable solution, if not I’ll post here on the forum. Running the PC on the Dell U2723QE's USB 90W power supply instead of the correct 130W doesn't seem to be an issue. 
As mentioned in another question here in the forum, "Missing drivers after Win 11 install", I made a clear re-install of Windows to try to get rid of an annoying issue. I had a clean W10 install with all the Dell drivers installed. Based on Dell recommendations I replaced my two old Dell monitors with a pair of Dell U2723QE in May -22. That didn't really work out well since the 9570 couldn't manage to drive two monitors on that resolution (3840x2160). Had many and long support calls which ended with that Dell Support were going to come back to me with a resolution. They never did. In the meantime I managed the situation by driving one screen via USB C (which also feeds power and Ethernet) and the other one via HDMI. I had to set the refresh rate of the HDMI monitor to 30Hz otherwise the screen would flicker. That wasn't an issue since I work with Office stuff and photos. I bought a tool to calibrate the colors which worked for some time but suddenly, sometime after summer, the monitors started to differ from the 9570. The tow monitors had much warmer colors than the 9570. Recalibrated and so forth. Didn't work. Then I discovered that Display settings suddenly showed 3 monitors, one disconnected. If this extra screen occured before or after having used Intel Update to update Graphics Command Center from the old Dell version a few weeks ago I dare not to say. Then came the Windows 11 but that update didn't help. On the contrary I got other issues with the PC, stoped to react, died and so forth. Well, the original Windows install was close to 2 years old so during this week I made a clean re-install of Win 11 on a reformatted HD and had Dell update/SupportAssist to complement that. Still 3 monitors but PC worked well. Today the USB C monitor suddenly turned black and in Display settings I still had 3 monitors, i.e. not the correct 2, but now with 2 monitors disconnected/disabled. Have tried to restart monitors and PC several times with no luck. So, what's going on here and how to resolve it? Lower the resolution is not the correct answer since then I have no use of these two, rather expensive, monitors. And it worked well enough for several months. Something else is the culprit, not with the screen but with the PC. Another, slightly newer client PC i tested, can drive both of them at this resolution so it's definitely nothing wrong with the monitors.
One of two extra monitors suddenly turned black...