For the Diode paralleled with the cap, there is a trick method of ST42 for this test.
The issue is caused by the diode direction auto-detection feature,
we have to set a detection time, and during the detection time, if the constant DC current source of ST42 cannot charge the Cap fully,
there will be a wrong judgment.
An idea:
Tweezers tries to pass certain current and measure voltages across. If the voltage gets exponentially changed you don't have to wait it to settle fully.
By a part of the exponential curve you can extrapolate assuming exponential curve with offset, amplitude and time constant and find out what will be final voltage.
This way you can find the diode direction quickly.
Also I don't think someone will complain if you put on a display "Capacitor - wait" as soon as you at the end provide useful measurement.
display "Capacitor - wait" is a good function, and we can have a try.
And if you try to use LED mode to test the diode paralleled with the cap, you can observe the voltage in real-time,
the voltage is increasing "linear" in the range, that's interesting as well.
ST42 uses a constant current source to do the diode test, so if we want to analyze the cap load, we can use the linearity increasing voltage to get the cap value.
But we still cannot get the diode forward voltage, until the cap is charged to the forward voltage(sorry for the bad use of
fully charged in previous comments)
We have considered some fancy ways to do the test,
Such as if the voltage of the diode test is continuously increasing or decreasing, we can assume there is a cap or inductor paralleled with the diode.
So the circuit model will be more complicated, but we can still get a forward voltage.
and then ST42 can switch to L/C/R test mode, and get the paralleled cap or inductor value,
the last thing is to show the circuit model and the value to the user.
In other words, ST42 can detect Diode/L/C/R and their serial/parallel relationships in DIODE test mode(Maybe).
Is it too complicated for users? sounds like this method is easy to go wrong