I went through the trouble digging up quotes for EWF's thread called "Method of the work" but apparently I can't post there. So I'll post here. I apologize for creating a bit of a mess on the forum.
The answer is yes, contemplating virtues is encouraged. Sometimes when I don't feel the impulse to destroy an ego, reflecting on what the virtue is helps. Here is what Master Samael says in Revolution of the Dialectic:
How could the words of a flatterer be transformed? [ Pride] It is by means of comprehension, of course. When one really comprehends that one is nothing but an infinitesimal creature in a corner of the Universe, one immediately transforms, by oneself, those impressions of praise, flattery, into something different. [Humility] One converts such impressions into what they are: dust, cosmic dust, because one comprehends one's own position.
In meditation, the dominion of the mind goes beyond the struggle of the opposites. In this manner, for example, when a thought of hatred or an evil memory assault us, then one has to try to comprehend it, try to see its antithesis which is love. Thus, if there is love, why is hatred there? What is the purpose of that hatred?
He later goes on to explain that it's important to find the synthesis. The ego is there, the virtue can be brought up, but what's important is to contemplate on both of them to arrive an the synthesis. You should get this book.