How does the Twin Flame Runner feel when they ignore their Twin Flame partner? 

From my experience, it is not a choice to ignore a Twin Flame. Still, usually, it is because the situation is not correct or because there is an obstacle in the way of the relationship so the Twin Flame Runner decides to back off. 

It is also out of fear and insecurity that the runner keeps running from their partner until they heal the core wounding within.

The runner Twin Flame is always haunted by the unconditional love connection and they experience the agony of being physically separated from their fellow Twin Flame partner.

The runner Twin Flame also goes through an intense spiritual awakening and they experience the energetic cleansing phases of the night of the soul. 

The runner Twin Flame learns all the complicated love lessons; they are challenged to grow and evolve into their authentic selves as time progresses.

In essence, the runner feels the same way as the Chaser and you always think of the oneness within no matter how far you drift from each other.