Controlling psu via bypass

Hi, I'm about to finish my rpi/octoprint installation. NOW I have doubts about the following:

-I want to be able to shut down the printer via octoprint.
-I also want to be able to shut down the rpi as it should (with the "shutDown" button in octoprint), and completely disconnect the power.

I've added a simple sketch with my plan:

When the main switch is on, the psu will not immediately be powered on. the 230 volt input is switched via a push button and/or a normally open relay.
This relay is closed as soon as the rpi is turned on.

the plan is to activate the psu (and thus the printer and rpi) with the push button at the bottom left of the drawing.

the push button can always serve to shut down the psu again (when rpi is shutdown with shutDown option in octoprint).

Once the rpi is active I want it to close the relay and bypass the circuit running through the push button.

When I leave the room for a long time during a print and switch off the push button, my psu, rpi and printer remain active via the closed relay.

now i hope that when i have switched the pushButton off, chosen to shut down the rpi via the shutdown option in octoprint, everything will shut down and the psu will not get any power.

Does this strange construction work or am I missing something?

Only thing I'm afraid of is the behavior of the relay. It is a cheap AliExpress relay board 230v 10A.

I have a smart plug (TP-Link) for my printer power and a separate power supply for my RPi. The printer gets turned off when I'm not printing but the RPi is powered on all the time. I can control the printer power with a plugin.

The RPi uses very little power and I have found it very useful to have it on even when I'm not printing. My main desktop is Windows and the RPi gives me convenient access to a Linux system. I have PuTTY and WinSCP installed on Windows.

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