My Polonius Performance Choices

I am acting as Polonius in Act II Scene 2 Pg 754. I started acting in the scene with an apologetic tone towards the King. It seems my character wishes to please the King in any way possible throughout the play. I shifted tone when Polonius, in my opinion, began to sound overconfident. He states "Hath there been such a time-- I would fain know that-- that I have positively said "'tis so" when it prov'd otherwise?" And he continues "Take this from this if this be otherwise: if circumstances lead me, I will find where truth is hid...." Polonius is also a conniving character and in this particular part of the scene he is indeed scheming and so my choice to act mischievous I feel is an appropriate one. An alternative to my acting style would be to act a bit crueler and maintain a viciousness throughout the scene.