Modeling slew rate limitation in ideal operational amplifiers

Hello everyone

I am having a little fun with modelling operational amplifiers, including BW, gain, GBW and slew rate (SR).
While the first three are very straightforward, I have had some issues with the SR. My initial idea was to use a voltage controlled current source and "clamp" the current using anti-parallel diodes with the diode's Ilimit parameter, but even though I limit the diode current to say 1 mA, it is perfectly capable of delivering 1.2 mA instead.

The figure above shows the result and what I've done this far.

The second thing is, it seems that diode D1 conducts reverse current, which I have no idea why it does so. Would you have any suggestions?

Is this at all the right way to model this or is there a better/easier way, I'd love to hear it.

Best regards