Measure resistance and capacitance with bias in low frequencies
If it were me , I would not only measure C &amp; tan delta but ESR as well and test to 10MHz.

You can use a scope rear sweep signal to drive an FM generator, but 50 Ohm is not the best source.

If you cant scrape a simple AC current source design to generate cap impedance as the output voltage, use a voltage source (ie. darlington emitter follower to drive the cap with an adjustment for DC offset +/-2 V and monitor current with a 1 Ohm shunt.   The scope can show the DC bias on one channel and ac coupled envelope synced to scope sweep.  This is a quick &amp; dirty method. XY mode of V vs I is another method.