For your consideration, I have this Astable-multivibrator via a classic Op-Amp Schmitt Trigger delivering a square signal (here 1.82Hz).
I am fine with the circuit with SW1 open as C2 is basically in Series with C1 making CT = 5uF.
However, I am not sure about the effect of SW1 being closed.
Can someone enlighten me?
Figure 1. Switch Open