Great, my posts from yesterday went with in the split thread....
So again:
I want to see the signal quality of the LiteON power supply (ripple) without having to open the power supply.
So I ordered usb-c breakout boards, which I will put between the power supply and the scope and can then measure.
And implement the suggestion of TimFox and supply the rigol scope with a linear power supply (and see what happens in terms of noise on the reference signal for the probe alignment).
Nice side effect, I can then also check the accuracy of my usb-c powermeter.
Today the boards arrived, tomorrow will be tinkered.