ECO mode being on apparently also stops counting the time when the monitor is in standby so shouldn't be any issues with the timer. I noticed I get a message with eco on stating the monitor will go into standby mode so in order to wake the monitor, you may need to press the joystick etc., with eco set to off, I never got this so presuming the monitor never enters standby mode at all with it off, only con with eco on is it does take about 15 minutes or so for colours to be accurately displayed, that and the panel refresh pops up every time when I wake up the monitor.
User Guide is now available: Dell AW3423W Monitor User's Guide MSRP: $1,299 Power Consumption: 0.3 W (Off mode) 0.5 W (Standby Mode) 42.3 W (On mode) 200 W (Max.) HDR certification: VESA DisplayHDR 400 True Black. Viewing area: 86.82 cm (34.18 in.) viewable area (measured diagonally)...
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Talked about there.